Instead of just fucking decimating you, bosses take care to attack in very deliberated and avoidable patterns which oh-so-conveniently also end up using its own weakness that, when used against it, reveals the only damagable part on the enemy.
Worse yet, "attackless" game bosses where the boss just rolls over for you to jump on its weak point.
Also, touching an enemy hurts you for some reason? It makes sense in more minimalist games like Mario or whatever where enemies just deadass don't attack most of the time, but let's use Hollow Knight as an example where enemies actively have their own attack patterns and moves; if the enemy isn't attacking, accidentally touching one of their pixels shouldn't be fatal.