I think a better solution than a side hustle, is to gather your friends or coworkers to propose to create, collectively, a worker owned co-op (of whatever idea seems profitable).

As it's being done collectively, there's more of a chance of it getting off the ground, as people could take turns working on it in their spare time instead of a side-hustle dominating your time.

Once it's established, those people could then quit their job and work at the coop.

There are credit unions that could help with startup costs, as well as guides on how to structure it based on other successful coops.