I actually came into Genshin thinking of Venti as an annoying little twerp, but he grew on me. I'd pull for him if I could, but I have 20k primos and nothing to pull on; I don't really dig Xilonen or Chiori, though I might throw a few at Nahida (having just finished the Sumeru quest line).
I feel like Genshin characterisation would benefit from using fewer characters but giving them more screentime. Natlan, for example, all the characters get a lot of screentime and personality. Mondstadt, Jean has very little screentime and what we get from her is incredibly meagre. You can tell the MiHoYo team has grown; speaking as a newbie who has only just gotten ready to embark to Fontaine, the writing quality in Sumeru was
much stronger than Inazuma/Liyue.
Mondstadt's basic quest line was actually pretty good, in my humble opinion, and if there's any qualm I have with Sumeru, it's that a large part of the story is confined to Sumeru City, leaving a large part of the map just entirely optional to explore. It does make the world feel larger, but at the same time, my time in Sumeru felt incredibly short compared to all the running around I did in the previous nations and in Natlan.