It has anilist too, that's what I use. I had never even heard of saikou before so haven't used it but I've never had any issues with aniyomi. It's perfectly functional in finding anything I want to watch and looks good. Can't do anything about your subjective preferences though.
Just that Saikou isn't just an anime streaming app. It's also an Anilist client. And it's beautiful and I love the animations and video player features like a skip intro button and it's generally just beautiful. You also can read Manga with it, but I honestly prefer Tachiyomi for that.
Aniyomi already has Aniskip (skip intros) integrated and can connect to your Anilist account to update your entries, automatically if you enable that, or manually.
I almost never go to the actual Anilist interface anymore, it works great.
I also use it to read a lot, and it has extensions for everything including Drama, Movies, Hentai, Porn...
Like I said before it's an Manga app that added Anime streaming functionality. I still use Tachiyomi for Manga though.
With Aniyomi I can't easily discover new anime, continue watching ones I added on Anilist on my PC and have this beautiful UI with really good, switch sources with a press of a button and have these fluid animations.
My current Aniyomi setup works pretty well and I am used to the sources I already use, maybe if the development is restored somehow in a different platform I'll try it.