I work with it often. Mongoose really bothers me since many of the methods are not exactly the same as just writing the query with MongoDB. I don't like that I have to know a separate API to use MongoDB's API.
That being said the Schema system is very valuable but I feel like you can do the exact same thing with Typescript these days. I use an embedded DB for my Electron app and the schema system I wrote in Typescript is just as good as Mongoose.
That being said maybe people should just move to Typescript and forget mongoose all together. But for me I much rather deal with the API I need to use rather than have another API on top of another API. You might say isn't that what Typescript is. Yes you are right but the difference is Typescript is fundamentally the same as Javascript except you have to add in the Type safety yourself.
I really enjoy Typescript though so I have a hard bias for it. I come from typed languages like C, Java, and Rust. So for me I dislike the lack of safety with Python and Javascript.