If you like Mathesar’s approach but need to work with MySQL, FDWs would let you connect a MySQL database to Mathesar for data entry and querying. This could be useful if you also have Postgres data and want to work with both in a single interface, or if you wanted things like cross-database queries between both DBs.

That said, if you’re only using MySQL, FDWs add an extra layer, and something like VisualDB, since it’s built for multi-database support, would likely be a more natural fit. The main advantage of Mathesar in this scenario would be if you want something open source and self-hosted (VisualDB looks like proprietary SaaS) or if you just like our UI and user experience.