Lots of great engineers will work for way less than a FAANG salary as long as it means not having to work for FAANG. $1m/year still won't get you all that much though.

Lots and lots of people work for much less or for free on whatever they like.

Problem is that doing "boring" parts of open source project maintenance is not very exciting for many top tier developers so it should pay at least competetively for experience or people will just burn out.

And while you can obviously fund a team of 20 on $1M/year outside of US whatever said team will manage to keep up to the level of quality is another question.

Realistically if you can work on a small and high profile project like tailwind you're gonna be snatched up by someone willing to pay you at or near FAANG levels