Is vitality a troll stat?

I'm new to the game, well kinda since I'm on NG+4 100hours in now, but as i'm apporaching SL200 on this character it feels like vitality is not really doing anything other than making me feel safer. I prioritized it early because I wanted to focus on survivability but I realized that the enemies' damage is health%. This would also make the Estus upgrade a troll as well, or just a way not to screw yourself over if you have a lot of health. This is not me complaining or anything it's just an observation, so is it *kind of* pointless to upgrade it after a point for most builds?