"Ekko waveclear because non-damaging Ult" 💀💀💀💀
Happy to have a good faith discussion about it.
I don't think I'm going to be able to change your mind on your perspective, but I'll just lay out some of where we're coming from (I considered your points as well but disagree with some):
1. Champ Matchups should make the game play differently: It isn't desirable for champs to play the same way every game, that might mean sometimes you need to make a tradeoff between being able to survive/win lane vs hit breakpoints vs scaling.
In the Viktor example, I think it's pretty reasonable that Viktor has strong laning as a tradeoff for lack of on-demand hard CC and difficulty in moving around the map compared to other similar mages
If Akshan just "had everything" (waveclear, roaming, gap closes/escapes, gank survival+followup, good sidelaning, etc.) then he just has no weaknesses. I don't think that's a reasonable set of strengths and weaknesses (at least for soloq); in organized play, there's a lot of differences
2. Just because a champion is difficult doesn't mean if you master them you should always be able to go even against other champs: I get that the mages are easy compared to say Yasuo or Akshan, but that is also by Design. They test different skills and not every champ is meant to be equally difficult in order to serve the millions of people who play League in addition to having as best a balance as we can for high MMR as y'all are much more sensitive to that
I do still think at the top levels that the high agency champions still on average perform better. Top 10 or even top 50 in regions has relatively low representation of vegan mages players (eg. Viktor/Ori) for example
Champs need to have good and bad matchups for the game to be fun and strategically interesting in the long term. Some games you're more reliant on your team to play the game and we think that's a good thing, not a bad thing; you can't be the main character every game, even though we understand that's really fun
3. Champions should be holistically balanced: Champs don't need to have equal quantities of everything; some champs should have more waveclear, some should have better roaming, some have hard cc, etc.
For champs that are giving up certain things that turn into core weaknesses, they're allowed to have other things that can make them powerful to the point of frustrating in those other aspects (eg. Viktor for laning, because no dashes or demand hard CC, Ekko waveclear because non-damaging Ult, etc.)
For Qiyana, it's probably more likely that we tap her down in the future however; she's certainly strong and falls more into the "non-clear weaknesses" camp