[alvarosevilla95]

Fizzi actually left his job at smash.gg on November to focus solely on the rollback project. He has a Patreon [0], and the community has shown quite the support: he gained 1k patreons in the 24h following the release. Another main contributor, UnclePunch, who's written most of the ASM to directly interact with the game, also has some Patreon support. There's also other contributors working on their free time AFAIK.

[0]: I'm not affiliated with Fizzi but I'm not sure if sharing his patreon would be spam, so I'll say you can find it in the project website from my previous comment.