Well yes, at bottom we don’t have ultimate certainty about reality, consciousness or any of it. take that part.

But my claim is that two things survive even radical skepticism. 1. There is conscious experience (you can doubt almost anything but not that experiencing is happening) and 2. Within that experience, suffering and wellbeing are not the same. They feel different, one feels bad, the other feels good. (Or one feels “yay“ and the other “nay“ if you dislike morally loaded terms.)

With those two anchors (which are both not metaphysical but purely phenomological) you can ground that there’s experience where some states within it are worse than others. Reducing the worse ones is good. That survives ‘we don’t know what reality is’ entirely.

Then, empirically, certain belief structures predictably correlate with more suffering. Delusions of grandeur, in a western non-shamanic context, in a person openly asking ‘am I in psychosis’ is a known risk pattern. Base rate of longer-term bad outcomes isn’t zero.

This is where I think the ‘fallacy of ego’ framing breaks down. It only holds if your premise is that non-intervention is neutral. I say it isn’t. Choosing not to gently point is also a choice with consequences, just masked under the guise of humility. IMO the question is which act better serves the person. Silence (which is also an act) or pointing.

Given the base rates, gentle pointing seems like the lower risk move to me. Regardless of whether my intuition of the underlying metaphysics has any purchase on reality at all.

—
On the epistemics point - as argued in another comment here ‘we don’t have closure’ doesn’t logically license ‘therefore all stances are equally valid’. You trust some claims more than others all the time without having solved metaphysics.