That, and executive pay, is where donations go, not to keeping the lights on. The running cost to keeping the servers running is about the same as that fund. It certainly isn't the case that engineering is "done" either, as the open bug count is growing constantly and huge swathes of the software aren't maintained and don't even have maintainers[2]. Just minor things of no importance to modern didactics like, you know, functional video support and rarely used, obscure, functions like uploading.
They have more important things to do like weird elections and appointing cryptobro "disrupters" to the board.