In my experience true ice isn’t that bad in terms of grip, it’s rarely so smooth that edges can’t easily grip on surface imperfections. It’s not fun to ski because it’s very high impact.

I think what most people talk about as icy and slippery that seems to form on skied off groomers is actually some kind of crust that is hard to get edge hold in because the snow is somehow very firm but not well bonded to itself either, so what little edge penetration you get just scrapes off easily and doesn’t support the ski. When I try to picture what is going on in such snow, edge sharpness doesn’t matter, you might penetrate marginally deeper but that just means you’re scraping marginally more snow off.