The thing is, everything boils down to how fed the tank is, in the end...
Of course, but that's no different than saying "everything boils down to spanking it, in the end", when talking about GW2. And technically, both statements are right. But, both statements disregard a lot of the fundamentals that actually make the combat interesting and challenging in both games, both ends of the spectrum.
Kinda sure that's part of what Miragee was getting at.
I imagine how much more fun something like Tahabata from Aion would be without a tank or a dedicated healer, but with short term invuln.
Conversely, I wonder how GW2 would be without. Would it be closer to GW1 in that sense? Would we be seeing less amount of damage from encounters to compensate? How would the meta perform with the current mechanics? Questions for an alternate universe.