But to answer your question more realistically:
* Familiarity
* Easy/built-in admin
* Longevity
I would also never consider switching an existing app from one to the other.
FastAPI make sense only if you write an api for a third party frontend or service.
But what is the sense to compare on a single feature? Obviously, Django doesn't cover 100% of use cases but, usually, you choose a technology that simplify you live overall not on specific aspects.
