> Are all startups at my age generally side hustles that become profitable enough to quit my day job?
Kinda, successes will generally be:
1) Ascended side-hustle (soooooo much luck involved on this one),
2) You basically already have minimal FIRE money or better (for whatever reason—saved well while earning high, family is rich, whatever) and can afford to take a couple years without an employer with negligible risk to your financial stability, or
3) You have a high-earning spouse to cover the bills while you give your dream a try
1 is easily the hardest and least-likely to succeed—so much less time to put into it, and you're having to steal free and family time to do it rather than working during... work hours.
(see also: getting started with a career in the arts, especially 2 and 3)
Kinda, successes will generally be:
1) Ascended side-hustle (soooooo much luck involved on this one),
2) You basically already have minimal FIRE money or better (for whatever reason—saved well while earning high, family is rich, whatever) and can afford to take a couple years without an employer with negligible risk to your financial stability, or
3) You have a high-earning spouse to cover the bills while you give your dream a try
1 is easily the hardest and least-likely to succeed—so much less time to put into it, and you're having to steal free and family time to do it rather than working during... work hours.
(see also: getting started with a career in the arts, especially 2 and 3)