Invulns: Problems and Solutions

[Absurdity]

Instead, at higher levels, with haste etc, you'll be pressing OGCDs nonstop and tanks have to constantly be juggling their tank CDs and tank spells to survive.

That can quickly turn the gameplay into a chore as well. Take ESO for example, you're constantly spamming abilties, like every 0.5 seconds constantly, either to keep up several buffs with different timers, several dots with different timers, spamming spells or magicka/stamina regen abilities all while spamming light or heavy attack at the same time. This might be more engaging than XIV for a while but you quickly get into handcramps territory and doesn't exactly require many braincells either because everything has such a low or non-existent cooldown.