It's also more about team comps overall and teamwork. I'm all for that, but not at the cost of individual skill which is currently kind of the case. League used to basically only have this via juggermaw comps and then adc's with ardent censer meta last year... but now it's trending more towards everyone picks to enable one or two damage champs to carry. Nobody else can kill anyone unless they're maybe 150hp/5%hp or less because they have no damage and the other guy probably just lifesteals or runs away no problem. I'm not saying poppy should 1v1 a vayne when they're both full hp, but it would be much more exciting if the game wasn't just... well our adc deals no damage because they massively lost lane and our mid is only good for killing squishies and they have a good frontline so... see you in 15 min when adc is relevant. Because even though our toplaner or jg is ahead by a meaningful margin, it only means they die slower... not that we can win a fight.
That's kinda how I feel pro play looks right now... depending on team comps of course. People aren't making the random amazing all-ins they used to to get a splitpush advantage and force the enemy to deal with them so their team can force baron. They aren't taking the risks because it's not nearly so worth it or easy to execute as it used to be. Not merely due to player skill improving, but rather because of a stupid over-emphasis on team. Can't fight this cuz we're down a player even if we are massively stronger. Have to concede giant wave because enemy jg showed up; no chance of 1v2 outplay or not worth even trying it. It makes for much less interesting games.
I agree champ kit and runes matter more than itemization too, although all 3 are somewhat important. I think what matters most of those 3 depends on the champ and team comps and can vary by champ.