That all said, to be clear, I do also find the survey data you linked in the other comment pretty disappointing. I do think it’s often quite possible to be donating 10% and saving 10% (or more). I think this should be encouraged for people who have gotten financially situated and have a rough idea of their longterm plans.
One last bit, that I realized I didn’t emphasize very hard in the OP: I’m also imagining this being pushed harder than Earning to Give is currently pushed.
The status quo is that if you ask “what do you need to do to be an Effective Altruist?” you get a murky answer, where “donate 10%” is one thing a bunch of people agree qualify, but so does working at an EA org, and maybe taking time off to learn does, and if you’re a student or poor it’s a bit ambiguous.
I would definitely oppose putting uniform pressure on everyone at an EA meetup group to donate 10% – there’s too many situations where the blunt instrument of social pressure would do the wrong thing. But I would be pretty comfortable putting uniform pressure on any EA with income to Earn to Save.