Earlier quoted context omitted.
Joins only make sense in analytical context as a tool to get some additional data into your report and almost never as domain modeling concept. People should pretty much hardly ever use RDBMS for their domain data... but since everyone learns RDBMS as their first DB, we have these horrible ORM frameworks on every corner.
Curious why you think this? I've found Relational databases pretty powerful, and learned mongo first.
Where are they really good is reporting. Analysts love rdbms. When I am on an analyst role, I love them them too. As an engineer I find them redundant.
More about domain modeling
https://dev.tasubo.com/2022/07/crash-course-domain-driven-de...