I'm of a similar opinion. I experienced all the issues of MongoDB's infancy; it wasn't a good time, but the mmap functionality seemed worth it at the time if you had enough memory or constrained your access patterns appropriately.

Nowadays, PostgreSQL has JSON/JSONB types, a full suite of extensions like pgvector and PostGIS, and I can scale with Citus or use it in any of the big managed clouds.

From a functionality perspective, MS SQL Server makes a more compelling alternative to me simply by way of its native graph database support.