I'm not into cryptocurrency at all, but I've read that some of the billion-dollar casinos in Las Vegas take it.

My domain registrar does, and it's not exactly a fly-by-night operation.

I think at least one airline does. Though I might be remembering that wrong.

I won't ever get into crypto because I like money that keeps working when the lights go out. But I don't think it's either as fringe, nor as mainstream, as the two sides present.