I seriously don't get it. 5e is already an edition with a lot of hp inflation and low lethality, mainly if compared to 2e. Why inflate enemy hit points even further? I saw an lv 4 spider in a cave with freaking 138 hp. Back on 2e times, Vecna, a Legendary demigod Lich had 150 hp. Demogorgon, one of the most legendary demon lords, had 200 hp. Myrkul avatar, 228. Goblins which you cold slay an entire army with an single fireball on previous BG, takes so much time to die. It is not fun or engaging, just boring.
138 hp is enough to soak 18 heavy crossbow bolts from a good(+3 dex/str) hunter. firing dozens of eldritch blasts, firebolts, arrow shots and polleaxes swings is not fun or engaging. Just tedious.
5e already has a lot of bloat. We don't need more hp bloat. Especially in a turn based game with slow animations and no option to use concurrent turns like ToEE had.
While i generally agree, i think the high health pools of some opponents are necessary due to design flaws that took place before.
On the one hand because of surface and status effect DoTs that are way stronger compared to regular DnD. And on the other hand due to the absurd hit rates. In BGIII you rarely have a hit chance under 85% due to high ground and backstab. Your avarage damage is at least 2 times of the damage you could achieve in regular DnD5e, especially if you take into account crazy stuff like shoving in a bonus action.
If we look at generic DnD5e: Just pick the Bandit captain. That is a NPC that gets thrown at you by at least 1 campaign as level1 bossfight. he has 65 HP. Now consider you are 3 levels higher than that facing the spider + you got like a 100% damage boost compared to regular 5e.... The Monsters need such a large health pool.
Unfortunate, but i think the "big health pool" issue is a symptome, not a desease. ´
If it had 80 health i would laugh it away in 1 turn perhaps 2.
