Yeah, but what they’re marketing specifically is aneutronic fusion. That’s helium fusion, which has never been demonstrated outside of a star. Hydrogen fusion, which we haven’t actually achieved much with beyond bombs is more managable. The difference is hydrogen fusion creates a big neutron flux, which needs to be isolated (the small part) and creates waste by neutron activating whatever it’s around (the cheap part, volume wise hydrogen fusion creates more radioactive waste than fission but it’s much easier to manage low level waste).

It doesn’t help that the helium is a primordial resource that has literally escaped the crust of our planet and floated out into space. Supposedly the moon has more.