As the other poster mentioned, lots of those things are on riots radar (although some sound more like low elo problems where the distinction of 'no counterplay' and 'I don't know how to counterplay' is relevant).
Still, you should understand that the meta is constantly evolving and isn't something that riot decides. As players explore new builds/strategies and patches occur, what happens to be meta always changes, and not always in expected ways. Sometimes a small buff to one champion can result in another completely unchanged champion to fall out of meta entirely, or even a small buff to a single item can result in entirely different champs taking over the meta.
For example, say a buff to item A occurs, then champions B, C, and D happen to synergise well with that item so they become popular. Champions B, C, D happen to be counters to champs E, F, G so they fall out of meta entirely, but champions H, I, J counter B, C, D so they become popular. Then Champions K, L, M, N, O, P end up having good synergy with with champs B, C, D, H, I, J, so then you have a bunch of new champs displacing the old 'meta' picks, all because of a seemingly innocuous change to one item. (And that process can continue too, as people then start picking things that counter K, L, M, N, O, P and so on, so even with no patches at all the meta can slowly shift.)
The designers and balance team aren't actually wizards so while they try to have a relatively balanced game, it's nigh impossible to know exactly how the meta will respond. Also, it's pretty much impossible for every champion to be balanced at every elo, so every champion having a 50% winrate and roughly equal playrates isn't even a goal.