MediaBay in Cubase is crap. It just stops scanning new, added files and every time you have to scan the hard drive to see new files. Plus this crap does not remember the last selected files in folders, as it is done in Reaper, for example. The best mediabay, if you can call it that, is in Bitwig, which instantly finds everything new and plugins too.
Plus, have you tried to mark a piece from a long file in the media bay and add that piece to the project? It’s crap and does it with great difficulty.