Except total HP makes a difference in the effectiveness of various spells like sleep. The bigger point being made by HP bloat isn't actually time to kill but all the ripple effects and subsequent changes to other systems that have to happen but upset the balance of how these mechanics should be translated to the game.
This is the slippery slope I am talking about. Every homebrew rule that Larian is running is going to have secondary and tertiary affects. A nerf to AC is a fat buff to Sharpshooter/Great Weapon Master. Suddenly now you are going to need to ensure the HP is scaled up enough that it's not a trivial tradeoff because these are popular choices and a missed attack really is supposed to be the tradeoff for the fat damage they give you.
