As someone coming off a decade of working there, I can tell you with some confidence that “you should use Firefox despite Mozilla’s leadership” is far more true and has been true far longer than you realize.
But you should also understand that original market-share vs ceo salary meme is a creation of Brendan Eich, presumably born of a grudge, and notably elided his tenure as CTO, during which the worst of that decline happened.
You should still use Firefox though.