Also, even if you just looked at the angle grinder video, you can see the claims aren’t really as presented. It’s very cutable, it just happens to eventually dull the cutter eventually. That’s what, a 2” billet they have there?
For their demo on a similar thickness steel plate, I think that most people would have an extremely hard time getting that far in 17-4PH steel let alone SS6xx like Inconel or any one of 100 different steels.
Mostly you would stop from boredom even in a world where the grinder wasn’t similarly full or broken by the time you gave up.