If you delete the SQL files Local will generate a new blank DB for the install when you Start. So yes the site will still open/function. You’ll just want to be careful not to Push a default DB up to WPE and wipe out your Database there if it has necessary content. If however you just created these sites on WPE and then pulled them down so they are effectively new installs, then that isn’t a concern.
I need to clarify a bit here. That /sql folder I showed is where database dumps go. This would be kind of like “checkpoints” or backups from when you start/stop the site in Local (or export) and it makes a new one and puts it there.
When you’re just actively working on the site, the database should live inside the Application Support/Local/run folder.