Hey @Malkazoid I appreciate your thinking on this. It definitely feels a little cart-before-the-horse to be discussing Niche management/ownership with no place (yet) to manage it.
It's also a little eerie to be getting glimpses of a project at such an early, might we say pre-natal, stage. There's still a lot of formation that still needs to happen. And, this thing will evolve over time.
Regarding the 20% fees, I look at that as the cost of doing business. If you make $1000, you pay $200 for the privilege and collect $800. This seems as reasonable as leasing office space, buying computer equipment, etc.
The tax burden is a real thing, though... and for that, I'd suggest (if someone plans to make a living off their Niches) to incorporate under a business license and mitigate that 20% as a business expense, and not get taxed on it.
Disclaimer: I am NOT an accountant or even particularly good at Maths.