Which database to choose for backend on node js (express)?

Question

MongoDB

All courses use mongu, on YouTube everyone uses mongu. What kind of discrimination, what is the reason for such a choice?
I read that if you need connections, then Monga is not suitable. Let's say I have a user base, each user has several profiles 1-10 profiles, each profile has 1-over999 clients, each client has its own products. Communication on communication.
Even if you take a simple blog, there is a user, his articles, and comments. Also connections. So why in monga courses?
Or is it suitable for such a product? Large loads are not planned, a maximum of 10-50 simultaneous users. Express js with rest api and vue js front. But the problem arose with the base ... I just want to do everything completely in JS, it will be easier to learn a new technology, and it will be easier to write a product in one PL. Before that, there was php and python and only back. Now I need to be a full stack on a couple of projects.

Answer 1

And what prevents you from using the base that you like?
Use what works best and what you know best.

Answer 2

they don’t use mongo on real projects, even if there is, it’s minimal. It is better to look towards postgris. Have you looked at Nest or feathersjs for backing? And then writing everything purely on node + express is not very cool, in terms of the fact that there are frameworks that give good solutions