Having played both, Star Rail is just different. It takes a “quality over quantity” approach, so the content it has is better, but there’s not much of it. There’s maybe 20-30h of game in there right now, if you do everything. Genshin’s more like 200h.
Being a newer game, Star Rail has some QoL features Genshin doesn’t have, but they’re not the biggest difference. For me the biggest difference is that I can actually play a TB RPG like Star Rail on my phone, while I want to play something like Genshin on PC.
As far as I know, the biggest downside of Toukiden 2 is that it’s a crummy port. It has no M+Kb support and the max resolution is 1080p/60 FPS. It’s not even an old game, so the 1080p lock is just bizarre.