I’ve shucked a few drives in the past but when there was a big sale on hard drives awhile back I finished decking my NAS out with 8TB drives that weren’t shucked as they came out to be cheaper than the ones in enclosures at the time.
The main downside is warranty really and some of the drives from enclosures need to have the power blocked on one of the pins to work (can’t remember which sorry) due to the type of drive they are.