I've done it twice. My gig for the last 20 years was a 4 hour work-week kind of thing. Years before that I actually made a good living selling a programming language (late 80s).
The tradeoff is that any venture like this is usually unproven. Your friends and family will probably not be impressed when you start, and of course launching any business is massively risky. Your spouse may be nervous for months or years. While I made out like a bandit, during that time I was also concerned about being tied to a single source of income. I tried several other ventures that failed, although never more than I could afford to lose.
The tradeoff is that any venture like this is usually unproven. Your friends and family will probably not be impressed when you start, and of course launching any business is massively risky. Your spouse may be nervous for months or years. While I made out like a bandit, during that time I was also concerned about being tied to a single source of income. I tried several other ventures that failed, although never more than I could afford to lose.