Wait, what? D&D isn't just a recurring series of combats after combat arena style. Well, not the norm anyway. That's hardly a trap ability if it grants benefits that affect the party in other scenarios (like being able to scout, retrieve items unseen, etc). And even if D&D were nothing but combat, it is not every PCs job to use their HP as a buffer. My wizard looks at you straight up scared. How about this. How about the rogue using his hiding to get a surprise attack the next round, attacking with advantage (and auto crit for assassins) and sneak attack damage? Yeah, he or she's not using their HP as a soak, but they are helping the party in other ways (mainly damage output). Yes, 5e rogues can do this. The gaming session we just did last weekend had the 6th level rogue do over 50 points of damage on a crit sneak attack. Way more than any other PC.