Who would receive that money? Only the core developers? Anybody with "commit access"? In which share? Will it detract voluntary contributions? How should other companies working on the same code-base be treated? Are they allowed to contribute at all? Do they get some shares of the funds?
All these questions (and many others) that have been discussed in the Debian project for a long time and nobody has yet found an answer that is acceptable to everybody.
Some sources:
* "Debian + Dunc-Tank.org = dissent" (2006) https://lwn.net/Articles/201488/
* "Paying (some) Debian developers" (2019) https://lwn.net/Articles/790954/
* "DPL: Debian project has plenty of money but not enough developers" (2020) https://www.theregister.com/2020/09/10/debian_project_addres...