By connecting creative economy types online and across the globe with their audience so that they can more easily engage in transactions/commerce is the definition of "venture scale". The only thing that separates business from non-profit is the tax designation, and how much ROI you plan to make for yourself/funders/public.
I see you getting downvoted, but I am fine with taking your comment at face value.
Here's the problem. Patreon, Buy Me a Coffee, etc are another middle man between creators and supporters.
That's another mouth to feed on top of Stripe/PayPal and possibly a Credit Card Company.
There is a very good reason PayPal has for eternity pushed/prodded and dark patterned users to death trying to get them to pay via bank transfer instead of credit card--credit card fees are business killers.
Now, why does this matter?
Even at venture scale, a Patreon/Buy Me a Coffee is the 2nd or 3rd middle man to the game. That means they need massive volume, but it's not enough. The perverse incentive cat is out of the bag and the good natured startup that just wanted to empower "creative economy types" starts doing all sorts of things that are in the company's best interest and not in its users' best interests.
Here is an HN thread from 18 days ago discussing the Patreon's CEO view that "the company's generous business model is not sustainable."
So I asked OP, in frustration because this seems like a failure to learn from history (very recent history at that!), but also in earnest--why should Buy Me a Coffee be a venture-backed business and not some other model.