That article actually shows that Mozilla spends most on software development.
It does have a lot of administrative overhead that it could do without, instead of laying off engineers, like they did. But the article itself is trash, due to complaining of $892,000 worth of expenses that seem dubious, in an organization that makes 500 million per year, which paints a certain kind of picture that's disingenuous.
The article may be trash as you said, but Firefox doesn't disclose how much they spend on developing Firefox web browser. Everything is lumped under "software development", and that's only half of their annual budget, Firefox certainly doesn't get the most of the budget.
If they spend most of that $200 million on Firefox annually and we have abhorrent text rendering on canvas elements for YEARS, something's seriously broken there.
It does have a lot of administrative overhead that it could do without, instead of laying off engineers, like they did. But the article itself is trash, due to complaining of $892,000 worth of expenses that seem dubious, in an organization that makes 500 million per year, which paints a certain kind of picture that's disingenuous.