Pal is not a class that tops the AC charts unless you go out of your way for it... but in a game with infinite speed potions, haste has risk and is automatically more balanced. It's also limited to oath of vengeance. Unlike oath of the ancients, it does not have an incredibly valuable aura, and would lose out on multiclassing potential by obtaining haste. Imo vengeance Paladin only peaks when multiclassed.
Any class can obtain a superior variant of the haste spell through chugging speed potions. Unless those become severely limited, the game will always be unbalanced 😴
