I lived through the MongoDB hype cycle.

For document databases, I'm more interested in things like PoloDB and SurrealDB.

Ex-Surrealer here. Thanks for listing us. Never thought someone on HN would cite us esp when it comes to MongoDB.

I agree mongo is overhyped and attracts a lot of web newbies who only know javascript and don't want to think through schemas, although one interesting newer feature of mongo is time series collections -- unfortunately they are a bit buggy but they're getting better seem like a legitimate non-relational use case.