Mozilla pays millions of dollars per year to their CEO, despite the decrease in usage and user base. Could be a symptom of a larger problem in the organization.
I've worked for nonprofits for most of my career, and have seen the insides of several. The most effective ones tend to have a small team on shoestring salaries and really need money. The least effective ones have a CEO making $5M and an executive team above $400k.
I've seen a lot of people argue that good people cost money, but they don't. I know $5M CEOs, $1M CEOs and $100k CEOs. The $100k CEO was by far the most effective.
That said, the Mozilla 990 doesn't look crazy. Many big nonprofits are bad. It's not an organization I'd donate to myself, but it's not one I'd discourage others from donating to either. CEO makes $3M, which isn't really reasonable, but the next-highest salary is $286k. That said, the whole for-profit Mozilla Corporation bit sketches me out. It feels like it might be a way to dodge IRS reporting regulations. I'd want to do due diligence before donating to a non-profit that has a structure like that (it may be innocuous), but I don't have time for due diligence when there are transparent nonprofits too.
If anyone knows a way to only support Firefox and not Mozilla at large do let me know!