The EFF is hardly a relevant comparison. Most Firefox users have no idea what the EFF is, but most Firefox users do know what Firefox is. (And even if they don't, and just know Firefox as "the Internet", as some users don't understand what a browser is, it's still a lot easier to tell them what Firefox is and why it's important than to explain to them the work the EFF does and why that's important.
I am not speculating here; I am speaking as someone who donates to both Mozilla and the EFF and reminds his non-tech friends and family each December to do the same.
The challenge with getting a critical mass of Firefox users to donate is not in convincing users that their web browser is worth ~10¢/month, but in the friction required to get them to make a payment the first time[1].
[1] (This is the exact challenge that basically every non-profit ever has faced with recurring donations. Some are better at solving it than others.)
How much does Wikipedia (something normal people actually care about) raise?
(That's the Wikimedia Foundation and does not include the local chapters such as Wikimédia France.)
As a comparison, the EFF received only $13 million in annual donations according to their last annual report: https://www.eff.org/document/fiscal-year-2013-14-audited-fin...