And there are no other major customers willing to pay Mozilla. Pretty much the only other options are Yahoo/Verizon (they are currently in a legal fight With Mozilla about a breach of contract that happened in 2017), and Bing (but Microsoft is currently on a mission to promote new Edge, and even included various pop-ups in Windows 10 to discourage people from using Firefox, so I don’t think they are interested in being Mozilla’s customer at the moment).
Mozilla has to stay in bed with google, and this is going to muddle any kind of privacy-related initiatives and communication from them.