NoSQL is even worse, data gets duplicated and then forgotten, so it doesn't get updated correctly, or somebody names a field "mail" and another person names it "email" and so on...

There is zero guarantee that whatever you ask the database for contains anything valid, so your code gets littered with null and undefined checks, and if you ask for example a field "color" what is it going to contain? A hex value? rgb(), rgba(), integer? So you need to check that too.

In my experience NoSQL is even worse, they are literally data dumps (as in garbage dump).