An admin interface would be wonderful, but given such a heavy API focus, I find Insomnia or Postman to work well enough for those interactions, so I haven't missed it all that much.
Seconding the SQLAlchemy friction though. Built-in ORM support would really help cut down the boilerplate required to wire FastAPI/Starlette models into the database. I think django devs feel the issue more acutely since defining FastAPI objects feels so familiar to making django models. But at the end, rather than having to wire up DRF serializers and viewsets, you need to wire up the database.
One other benefit to taking a more opinionated approach to database interactions: with a sensible-defaults-but-customizable user model, FastAPI could offer token based authentication/authorization out of the box by implementing something similar to Django+DRF+Djoser endpoints
Anyway, seconding the gratitude for this wonderful project, and really looking forward to using it more!