Ask HN: Form Website: NoSQL vs. Relational?

I have limited experience with databases, so this has been tricky to answer for me. I'm building a website where users "own" some forms they can send others to fill out. Later on these forms get compiled together and they can see some basic analytics on the data.

At the moment these forms are premade but long term I'd want these default forms to be extensible. I'm productionizing my demo (built on MongoDB) and trying to figure out if I want to migrate to Postgres.

It just seems like building something like this would require creating countless tables for every different form type adding much complexity. I've been pretty happy with Mongo's data validation. At the same time a lot of this data seems relational and I'm worried this could turn into a nightmare over time on Mongo. Seems like no one has good things to say online about it.

Not sure if anyone has input and could point me in a direction. Any help is appreciated.