And Helion has built upon "a ton" of work from predecessors as well.

The quoted argument is basically "it hasn't happened yet, therefore it can't happen". Why does this argument not also apply to SpaceX, for all the things they've been the first to do?

I get that skepticism is warranted, but please don't cross the line into blatant technical nihilism.

Skepticism is more than warranted. I would be skeptical that they could put out a working reactor in 3 years even if they had already established the technical and commercial feasibility in a lab setting!

I’m curious if you’d make a bet on this and how much you’d wager?