This is cool - there's many other less well-known plants and fungi that could aid neuro-genesis - though I'd wait for serious studies and not get caught up in marketing hype.
What I worry about sometimes is whether or not taking something to make you better/smarter/etc. is actually a good thing. I don't mean that we can't or shouldn't better ourselves. But we should look at why we want to be smarter or more focused or harder working. If it's for something worthwhile, then great. But if it's so that you can more effectively screw over your fellow humans, or put up with an arsehole boss's impossible work goals, then I'd say you need to reassess your choices.
Lions mane has shown to cause neurogenesis and is not active. Psilocybin has a few other effects that seem to compliment the neurogenesis. Certainly needs to be studied more and I admit to feeding the hype a bit.
As far as why do we want to become smarter? That's a tough question as it seems to come with a cost. We have Amish communities where I live and though they lack in education, they certainly carry smiles on their bearded faces. It seems a lot of brilliant people are not the happiest and carry a heavy load on their shoulders. I think a happy life is a more valuable goal.