The NFL is constantly starved for starting caliber offensive linemen, and that’s particularly true of the offensive tackle position.
Humans who are capable of playing offensive tackle at a high level are just rare. The position has a high athletic premium, and there just aren’t that many men walking the Earth who are over 6-foot-5, with long arms, 300+ pound frames, and the movement skills to block NFL caliber pass rushers.
So when a prospect comes along who checks all the athletic boxes and shows he can play the position at a major college, that prospect is often drafted highly.