Disclaimer: I am the CEO of Code Sponsor (https://codesponsor.io)
Code Sponsor is trying to help provide those who are maintaining OSS projects with untethered sponsorship funds. They can go about doing their business on the projects and be making money through sponsor-based ad revenue. This provides them with the incentive and finances to justify continued support on those projects that end up being abandoned when unfunded.
I agree that this is a HUGE problem that needs to be addressed. Code Sponsor's approach is to go where money can scale: marketing budgets.