Opinion on state of overall balance?

I always played off and on but the past couple of years I've seen some pretty unbalance champs. Here my opinion on champions that were OP at the time.

1. Jax: E gave you passively increased dodge combined with Ninja Tabi you could evade like 40-50% of the incoming auto attacks.
2. AP Master YI: W heals almost max health, usually never died unless you have ignite ready. His Q hurt like a bitch.
3. Riven: I don't remember too much but I know around s3 she was OP for some reason till Riot nerfed her to dust.
4. Twisted Fate: global ult with low ass CD.
5. prob the most OP champ ever existed ever since LoL was released, old Xin Zhao. his current w passive was his innate passive(only that his innate was stronger) and his w granted passive attackspeed (up to 60% if i recall correctly) which got doubled on activation of his w, but also every hit while it as active granted 1 second cooldown reduction on every spell. his ult didnt knock back but had a lot more damage back then. same with his his e and q. also his e had a shitton of aoe and a higher cast range.

Do we see any champions broken today? not really, the game came a long way but its pretty decently balanced.

It's better than it was. The only champ that could use a rework imo is . He is in every game I play and does well no matter what. I feel like if they remove the armor pen from his ult, make his Q a knock back instead of a knock up and let him use his ult without the knock up restriction, he would be fine.