Having been part of a billion dollar acquisition myself, I can attest that for the vast majority of people (myself included), it was equivalent to a nice bonus. Perhaps more people need to realize that and internalize that before they forego the higher compensation, and easier workload of an established company?
The only thing that will realistically get founders to share more equity is for the market to demand it. Personally I would not sign up for another startup journey unless I felt there was substantially more upside on the table. Otherwise, you’re better off joining BigCo or go further and start your own thing and get founder equity.
FWIW, I wouldn’t begrudge the Github founders... they’ve done an amazing job over a very long time. They rolled the dice and made it happen. Hats off to them!