depends how you build it and what your goals are,
someone could probably make a totally passive aura build that clears even Celestials, with enough patience
whether it would be fun or “tolerable” i couldn’t say
here is an older example of a passive VF+censure build that was good enough to clear Crucible at the time with some patience (over 2x as slow as meta time) [1.1.7.2] Peaceful warrior: no attack, no spell attack, no retal meme Purifier build. 150-170 clear (+actually strong, endgame-viable version)
i don’t remember how far RektbyProtoss aura focused, infiltator?paladin? got, but iirc it atleast cleared ultimate HC, you would have to check his YT channel to see [HC] Build & Guide Collection by RektbyProtoss
again, 100% passive aura builds like the agrivix purifier banana demonstrated is a bit more on the rare side, simply because adding player actives drastically improves things, another ex [1.1.9.0] Peaceful warrior goes on the offensive
from my own experience you should atleast be able to cobble together a semi passive build like aura infil/embers calling sabo that can do Ultimate dungeons and SR 65
never bothered with Celestials myself for such gimmick build (not enough patience), but would not think it impossible
^and either way it would be slow(er) for regular farming than if including just “some” player offensive activates, even if just a single like auto attack/fire strike in the VF embers saboteur example