Alright back and ready to debate again!
Well sure, changes to the game dictate what the current meta is, but in a different meta there would still be optimal picks. They might not be as easy to analyze, but at the end of the day a protect-the-adc comp is going to have certain odds of working out and a win-as-many-lanes-as-possible-and-snowball comp is going to have certain odds, and turtle-and-outscale comps is going to have certain odds, and they're all but certain to be different in each case, and there will be champions who are statistically best at doing those jobs within each comp, so comp-X with champ set Y is statistically going to be the best, and there will be the best count comp to that, and some variations on each due to pick/bans.
See my issue with this is that certain comps in their entirety can become all but invalidated, so any champions that only function well as part of those comps are invalidated too. Lets take a protect the ADC comp. Currently with the amount of burst available to assassins you can have two assassins on your team, thereby invalidating this entire comp because in general even a protect the ADC comp doesn't have enough power to save an ADC vs two assassins in a meta where damage is this high. Especially since that type of comp is a scaling comp which means the comp itself is bad, the champs in it are bad, and altogether it just isn't a justifiable option in this meta.
Sure you can do it, but it isn't a good idea in organized competitive play.
I don't think you made a good argument for saying players aren't more serious now than before. They absolutely do have the option of picking their pocket picks, as the champs are still unlocked for them, and the button still works. I don't doubt they'd love to pick them, but they have to take the game seriously, and pick the 'best' picks. If there was a time when they picked their pocket picks instead of the 'best' pick, that implies they were willing to take things a bit less seriously. I get that the win chances between pocket-pick and 'best' pick may be bigger now, but if you're ever not picking the 'best', then you're not playing completely seriously.
I think you are overlooking the power that a pocket pick brings to the table. The element of surprise, the player playing better on that champ, etc. Add a lot of power to pocket picks. You think that when Viktor or Urgot first made an appearance the enemy team knew how to deal with him? That adds a lot of power to the pick and makes picking it completely justifiable.
However when the meta makes those champions themselves very weak they aren't justifiable because the power gained from playing something the enemy doesn't know how to deal with is more than canceled out by the weakness of the champions. Viktor was a huge surprise pick that no one expected. The power he offered surprised everyone and he remains meta to this day, so it isn't that players are more serious. Viktor was a plenty serious pick who was able to flourish due to nerfs to other mid laners.
It didn't stop him from being a pocket pick that dominated the field. The issue is that these days there isn't a new Viktor hidden around. The meta is so heavily crushed by champions having to deal damage in bursts that the only other things that squeeze in are champions that are just really strong in an overbearing way and those champions aren't a surprise at all, example being Poppy.
Also, I didn't necessarily say the players themselves were more serious, but the scene in general. The players may be as laid-back as ever in terms of their own preferences, but team-owners and sponsors and so forth probably aren't, and shouldn't be, as the stakes are getting ever higher with more and more eyes involved and larger and larger sums of money, and that forces the players to be more serious or lose their status as a pro player.
I think that is a fair point but I really think you are overstating it. I haven't heard a single player with this complaint and they tend to be pretty vocal about this stuff. As the majority of sponsors, team-owners, coaches and so forth are the same that they were 3 years ago, just shifted around a bit I find it hard to believe that the scene has really changed much on their end. Sure they might be a bit more focused on winning, especially with SKT winning another year in a row but I don't think they would be discouraging pocket picks. If anything they would be encouraging them for the most part because pocket picks have proven incredibly effective in the past when it comes to pulling out wins where the team had to win or get kicked out.
I feel like I should mention I only really pay attention to worlds for what should be the pinnacle of serious play, but even that has had occasional flickers of non-serious play if theres an expected skill gap between teams (e.g. a korean team versus an IWC). I'm pretty sure that one of the take aways from season 6 worlds was that the skill gap between all pro non-korean teams is getting much smaller than it once was, so something is changing that isn't simply the game given all the teams are playing the same game. That something is the infrastructure and how serious it's being taken imo, which clearly has changed over the seasons, and likely will continue to.
You could also make the argument that as the Meta continues to un-diversify it would lower the skill gap between teams as they all start to use the same strategies. In season 5 for example splitpush, tank, lane swaps, poke, protect the ADC, and wombo combo comps were all effective strategies with pretty similar winrates. It made the teams that were really exceptional and able to master more of them much more powerful because they could reliably build comps that countered their opponents comps. It made the teams that were only really good at say, poke and splitpush comps incredibly easy to beat for teams that knew more strategies since you knew what your opponents were probably going to go and if they go for another strat you would know they wouldn't be able to perform at as high of a level and beat them anyways.
It really bumped up the skill ceiling for whole teams who were able to master more comps than their opponents and placed a lot more power in champion select. Narrowing the number of comps that are viable would also cut away much of the skill element in comp building, one of the major skills of a team back in season 5. Removing that lowers the skill ceiling, pushing team's skills closer together.
Now I am not saying that is what happened, just pointing out that your argument can be attributed and support many different ideas.
Within the lcs and various other tournaments, theres probably expected skill gaps between teams which would contribute to willingness to deviate from 'best' picks. If the number 1 team from a region was facing the number 2 team from a region, I would be very surprised if either of them did anything but the 'best' picks. On the other hand, if the number 1 team was facing the weakest team in the region, I'd expect they might pull out their fun picks provided the skill gap between the number 1 team and the weakest team was relatively large (Edit to add: the reverse case of a team expecting to lose pulling out the pocket picks for fun is also a thing since they may as well have fun, but when the match is expected to be close, I don't expect risks.). I couldn't easily find what kind of team match ups were involved when urgot made pro play appearances (mostly getting results where pro players use them in solo queue), but I suspect they were in match ups were one team was already pretty heavily favoured to win. If we're not seeing similar so far in season 7, that might be for game related reasons, but it might also be that the skill gap between the best lcs teams and the worst lcs teams is smaller than it was in previous seasons, which would be in part due to increased levels of seriousness of all involved to push people to the highest levels.
See pocket picks were originally for when you were vs a challenging team. They were surprises that the enemy team couldn't react to well and didn't know how to play around and that the player using them could do exceptionally well on. Them being only played vs weak teams just shows that the meta is so constricting that the surprise/skill factor on them is overshadowed by the meta power discrepancy.
All that being said I do agree that a bit more seriousness may have crept into competitive play, but I don't think it is the major factor in the slightest.
