Your problem was experience and skill, not Firebase. You needed an software architect on your team. A bunch of soon to be graduates can’t be expected to succeed in building anything complex unless you are all software geniuses. (Which does happen sometimes.)

I have built production systems with AWS and Firebase. There are pros and cons to both, you can succeed with either. I have built multiple web apps with Firebase for the past 3 years with success.

When I read your article it is obvious to me that your team skills were your biggest problem. For example, if you use typescript interfaces for your data objects you will not have developers misspelling the user_id field.

Find a software architect for your team. A person 2 years out of college is not an architect.