Well, it’s just a company trying to hype their product, so definitely craze territory.
There is some good stuff in shrooms as others have already covered, and most of that will be present in a broth made from them. So it isn’t totally bullshit. But it also isn’t coffee in any way at all.
As far as making it into a power yourself, you likely wouldn’t get the same results since drying the damn things, then processing them is not exactly a learning curveless thing. Definitely doable, just takes some effort to get nailed. I used to do it to add flavor to stuff without having the actual pieces of mushroom present, since the texture is offputting to a decent number of people I have cooked for. Not worth the effort imo, but maybe if you’ve been recommended to have a specific mushroom by your doctor, it would be worth it.