Items have become too overloaded. A problem cheered on by those unwilling to learn when and why.
Perhaps it is just my stance having been one of the bruiser/assassin players who thinks that marksman should be really easy to punish for their mistakes since they build glass cannon but it seems like less is allowed to happen when marksmen mostly control the outcome of the game. Yes this is me saying I would rather deal with a fed LeBlanc early season 4 instead of a Fed Vayne now since there were things you could do to contend with the LeBlanc. A Leblanc never once used Qss against me to get out of a stun but vaynes have done it many times but it is far more common since she gives nothing up in getting a QSS today.
Health has been massively nerfed since season 2. Yes I remember Warmogs maxing out at like 1300 and having a lot of Hp5 but also having to be stacked based on champion kills, assists and CS. Force Of Nature being the go too MR item since no other MR items besides BV were decent. To top it off % health damage is literally everywhere now compared to season 2 where something like 5 champs had it somewhere in their kit and you had to get Madred's bloodrazor for any kind of item % health damage which was considered so bad that only some vaynes, Udyr and WW might get it.
Wit's end being a good rush item for some champs at the cost of it not scaling the best into late game was nice in season 2 since it was limited in what it offered for an item slot. It was a sacrifice of late game power for early to mid game potential.
Sure there are more items today but they are all so overloaded in their final build that there is no sacrifice in getting any of them. You don't trade some good damage in getting a QSS over a ghostblade anymore and even things like Hexdrinker which was alright but not the best have been given such a strong build option that there is no sacrifice in getting certain items that were there to allow a way to contend with potential issues early to mid game but not scale the best into late game.
Yes I am saying that this game was better when you had to give up something in order to get something situational. Those days are long gone and with it goes a fair amount impactful decision making. CoH before athene's was a joke because if you learned to play smart you could manage mana. You sacrificed an item slot to greatly reduce mana issues in getting CoH and in turn it meant less AP and the like.
Riot Yes I am going to say it. Making so many items that contend with a problem without trading something in getting them has left the game worse then it was in season 2.
It is not going to be solved over night and is likely to late to turn back but it all seemed to start with simple additions like athene's, Maw and scimitar. Generally liked by players mainly because it took a fair amount of real decision making out of their playing as to what should be bought when dealing with a given threat. Would you rather have more damage or be able to use a QSS and get out of the WW ult so you can actually be a part of the fight? Decisions like that were actually rather showing as to if someone was going to win or lose a game. Not anymore since now QSS builds into an item that has a better QSS active, 35 MR, 75 AD and 10% life steal. There is no tough decision making with builds and no real sacrifice to be made in getting any of these items that once were a choice to contend with a problem., not even 30 damage worth of sacrifice in getting the QSS today so you can contend with a potential issue like WW who has since that become either OP or UP depending on the patch.
You want an example of a reasonable sacrifice that might be bought against the right enemy team comp? QSS + a single pickaxe so it has the active of scimitar, 40 damage and 35 MR and a cost around 2500 that is all. That would be understandable since that is far from an ideal item but would be worth getting against some enemies like WW and Malz.
With the lack of sacrifice in situational items the game is far less impacted by item decisions then it was 4 years ago. This is in fact a lowering of the skill bar that is overall bad for the game.