That may work for some businesses, but IME, the people who hold the purse strings generally aren't ok with just giving money to a project without getting something in return. Especially if it isn't a 501(c) non-profit they can get tax deductions for. I think it is actually a bit of a gap in tax law, because I don't think such a donation would count as a business expense either if you don't get something concrete in exchange.

You just described Github Sponsors, Tidelift, and a couple other less well known competitors. It's a business opportunity, but not a great one from what I can tell.