I think Firefox has a sizable minority of users that are aware of its importance and would donate for "a fucking browser".
Tbh I would also donate for a nagging team that publicly pressures various corporate sites into continuing to support firefox (like my cell phone provider, i can't download invoices with FF since 3 months).
What I wouldn't donate for is "me too" initiatives like "AI" and corporate bullshit. Or even charity initiatives if done by Mozilla. It's not Mozilla's job. Their job is to keep a working browser alternative up.
And as it's been stated in techie discussions time and time again, they don't need to be that large for just "a fucking browser". But that would diminish the CEO's status so we get what we have now instead.