My "teams" are usually more varied then this, but it's either Ganyu and/or Zhongli so the others don't matter and just get friendship carried.
For a more "proper" team, add Barbara for freeze and Diluc for everything ice.
Xingqiu if I need to swap to Diluc for main dps (which is literally only for ice flower and wolf, I think).
Venti and Bennett in Abyss when needed.
I have some other chars either built or half-built but there's like literally no reason to ever use them, so meh.
Currently really struggling to get motivated to properly build other chars, cause none of them are even going to get close to Ganyu. It doesn't help that I actually really enjoy Ganyu's playstyle (charge shot sniping all day every day), which makes it even less desireable to focus on others. After I reached 70/80 with everyone to collect their ascension fates it feels like there's no real point to anything anymore.
I have no real issue with working towards ascending, talents and weapons since that's all nice and finite, but as soon as artifacts enter the conversation I'm losing every and all motivation and with artifacts contributing so much it feels like working on the other parts is useless.