I'd believe this if that same money wasn't required to keep the lights on. Easier to just stop paying it and wait for them to run out of runway.

Two possible outcomes of Mozilla losing Google's funding: Maybe Firefox evaporates away to nothing, 0% market share, and now Google loses the fig-leaf covering their browser monopoly. Or maybe Mozilla loses their ineffectual but greedy leadership, allowing people who believe in the mission to step into those roles.

I think Google prefers the status quo to either of those scenarios. They prefer it to the tune of hundreds of millions of dollars a year, for that is how much they pay to perpetuate it.