I think part of the reason the Flask extension ecosystem is so weak, is that most problems solved by an extension have solutions that are relatively small / che

I think part of the reason the Flask extension ecosystem is so weak, is that most problems solved by an extension have solutions that are relatively small / cheap to build in-house. These things are difficult both to depend upon externally and to maintain, due to the dependency/upgrade issue you mentioned. For an example in a similar ecosystem: at a previous company, at one time we used SQLalchemy-continuum for audit tables. We found some bugs and were not able to upstream them. When we wanted to upgrade SLQLAlchemy to X.Y, we were stuck with this dependency that required SQLAlchemy X.Y-1. After a few years, we realized it was cheaper to cook up a SQLAlchemy-Continuum subset that met our needs, so it'd be easier to keep in line with SQLAlchemy. It's a very different mindset from Django; I think there's an appropriate context for each.