Something like Firefox is so complex that I could not fork it and make my own. I mean, I could, but the amount of changes I could put in would be trivial unless I'm getting paid full time. Even if I was paid full time, realistically, one person paid full time, no matter how good, just can't make an impact in the browser today.

I'm not paid full time to work on a web browser. As a volunteer, I can't find the time to dedicate to that. I could do a few lines here and there if I really got dedicated, but like most people, I have a life. I have kids and such. My retirement account won't fund my midlife crisis to quit my job and work on a web browser, so I depend on something to build a good browser. And that is assuming I even would work on a web browser if I could afford to do whatever I want full time. There are a ton of other activities in my community that need volunteer help, some of which I'm helping a little bit, but I could do more for.

I, like many here, have wished that we could donate a small amount to Firefox every month to fun development, however it turns out that the Mozilla Foundation does not fund development of Firefox and so any money would go not to Firefox but to other causes of which I may or may not support but are not a web browser which is what I want to support.