It's not about whether you need buffs to play or not, but rather what usefulness it can offer for special missions.
It reminds me of the days back when a lot of Inaros played, because this frame can't die even to Brain AFK. Some players then used this to join for Eidolon hunt or similar events. Every player with some experience wanted frames and auras to make the missions quick and efficient. Frames like this with Physique or Steel Charge in the aura are not very helpful.
Of course everyone can play whatever they want. I just find it boring to always see the same frame. If Revenant's survivability wasn't so excessive, players would also look at other frames.
I find Revenant and especially its augment for the Mesmer skin very helpful for the group. But, for example, the far too many stacks he has should not be more than 5, as the augment for allies allows. So Revenant would also be forced to maintain the buff for everyone at all times. I miss team buffing with most Revenants anyway.