While much of the online noise about Genshin Impact builds and character guides focuses on maximizing DPS for a particular character, damage isn't the be-all and end-all of godlike power in Genshin Impact.
UPDATED QIQI GUIDE: How to play, best artifacts & weapon builds, team compositions | Genshin Impact 4.2
The thing about a god is indeed not just invincible power, but invincibility. Ask Kratos: it's usually hard to kill a god, because they're not exactly squishy.
And that's where a specific loli zombie from Bubu Pharmacy comes in handy.
Qiqi gets all five stars not only for the insane healing she provides to her team, but also for the specific way she heals. She can buff the healing of a bruised and battered team, or supercharge a damage dealer's HP and turn your main DPS into a vampire god. Or you could even go the "best of both worlds" route and build her as your main carry – an expensive, but 100% viable strategy to employ.