Because of the petrification, which makes me fall and take insane fall damage (>1k) where I'd have lost <50 HP if I'd fell normally, if I didn't have wings. (Which I do). Lucky Horseshoe doesn't help either. Even grappling can't do anything (if you're grappled, it is undone).

Additionally, the Medusas petrify, like, a thousand tiles away (from the moment they spawn?), making countering them all but impossible, as they aren't even on screen when casting.

If you could see them, even at the very edge, then it would be a little fairer, but right now it's just plain dirty.

Which means that the only ways to build without dying every ten seconds would be to either stand on a solid platform at all times, or completely wipe out the biome. Both are extra tedious. (Or use calming pot to die every minute instead).

(You can build houses and temporally move NPCs too, or use other ways to invalidate their spawn (like walling everywhere), I guess, but it's even more tedious).