They are not burning money, they are employing people like you directly or through 3rd party partner companies. The beneficiaries can decide themselves how to spend money. They can live a good life or help others.
Somehow Facebook getting a huge amount of money. They are distributing that money to a million people (directly or indirectly to employees, share holders, employees of 3rd party partners). Some people are getting billions and some are getting $100s.
Instead of handful of people in Facebook management deciding to be humanitarian, you now have a million people deciding what to do with their portion. It is that simple.
Seems like you are the one with an outdated model of how money works.
Over the last couple decades it has been moving up at an ever increasing rate instead of down.