Here's what you need to do, to make your League experience more enjoyable: Stop viewing things linearly. Part of the problem you face is you extrapolating three champion releases in a roster of 138.
Just because champions from Ionia do not suit your fancy doesn't mean that League is going in a "bad direction." That is the definition of a slippery slope fallacy. It may just be League trying to include a certain demographic. In this case, it was those who are in love at a younger age (Xayah and Rakan), and those who love seeing cold-hearted badasses (Kayn). Their designs have an eastern or "anime" influence as you put it, because their region is Ionia.
You were blessed with a continuous two year time period in which every champion released was perfect for you. However, it is wrong for you to say you personally deserve to be catered to. Perhaps people disliked bard because he never had a voiceline that wasn't musical, or perhaps they hated Aurelion Sol for not being Ao Shin. I personally hated it when Diana got a blood moon skin, and I complained about it. Guess what? It didn't change a thing, because more people wanted the skin. But life still went on and I found new things to adore. I get that you don't like anime, or that you don't like "edge" because you certainly sound like a thirty-some world-weary adult, but they are players too, and they deserve champions that they can cherish just as much as you do.
Now onto skin lines. You complained HEAVILY about Star guardians, but have you considered the rest of the skins that Riot released this year? Arcade, Lancer Zero, Pentakill, Omega Squad, SKT, VS. skins, Soul Hunter, Chemtech, Pulsefire, Cosmic, Dreadnova, God Fist, Toy Set, Dragon Sorceress/Slayer, Festival, Heartseeker, and blood moon. Because Riot releases one, maybe two (if you count blood moon) "anime themed" skin sets, suddenly everything else is useless? Are you seriously saying that they have no variety? I think that that particular point you made is completely asinine. Maybe you feel out of place with Star guardian, and hey, for the most part, so do I, because I don't any hold special love for the magic girl genre. Except to a bias such as yours, all anime is the same, and holds no value, or meaning. I think you need to reevaluate exactly which demographic you want to protest against, because honestly, I think you're using some vicious stereotypes to generalize the anime community.
Finally onto my last point: you seem to think that league follows a single path, when in reality, it's a bunch of parallel paths that complete at different times. Star guardian skins were in development at the same time that the Omega Squad skins were being worked on. Just because one path doesn't lead where you want it to doesn't mean the entirety of the company is following that path. If you want all the paths to point in the direction you choose, I think we all can see who is actually being immature here.
You only either post to complain about content that you don't agree with, or praise new content for specifically not being the content you disagreed with. I think that that behavior, especially in an adult is incredibly immature. Furthermore, you usually rebuff counterarguments with the same rhetoric: either by ignoring/acting indifferent when you can't come up with a proper response, or devolving into self pity, ie. "you're saying I should uninstall because I'm too old." The few times you actually do offer some useful suggestions, they're usually paired with some heavy criticisms of what you disagree with, ie "make champions like bard, Camille, and Aurelion Sol and not edgy weeb champs like Kayn." That's not positive feedback, that's demonizing previous work. It's this manner of speaking that incentivizes people to disagree (read flame) with you, even if you actually have a valid request. You've made a false dilemma: either you agree with me and are a mature player, or you disagree with me and you're either an edgy child, weeb trash, or immature. That is a change you need to make within yourself before you can start telling others how they should think.
TLDR; three champions and one skin line don't define all of league nor do they represent the entirety of Riot's future plans. You need to stop viewing these as a step by step progression of events and start realizing that different teams work on different content simultaneously with deadlines that they reach one-by-one. Stop demonizing both Riot and the players who enjoy characters like Kayn, Xayah and Rakan, and stop pretending like Star Guardian Skins define future skin releases. Every skin or champ is not going to appeal to you, just as it isn't going to appeal to me; find what you love, and cherish it for existing. Don't criticize others for what they love and the content they want because it exists. They deserve it just as much as you, and don't get me wrong, YOU DO DESERVE IT. It's just that every dog has its day, and this time, it was Star Guardian fans.
