It still doesn't make it a DB-based solution. Calling it as such is confusing, especially to the long-time Org-mode users. They value the nature of all the data being in plain-text. No valuable data ever goes into that DB, it's purely for indexing. You can safely delete it any time, it just gets recreated.

Saying that Org-roam is DB-based is like characterizing any codebase hosted on GitHub as "written in git". Even though, speaking pedantically, that's true; it still would be nonsensical.