"Are all startups at my age generally side hustles that become profitable enough to quit my day job?"
Mostly that is the way BUT not the only way. Have you saved any money to take this risk ? Can you work for say 12-18 months and not worry about paying bills if you quit your high paying job ? If yes, then by all means you should consider it. If you don't have anything saved and you don't live below your means, tough luck. You have to give up somewhere if this is important to you.
Another option is to use your money and buy a small project/business that has some cashflow coming in already. This may not be a hockey stick high growth startup but may be you don't need/want that ?
Mostly that is the way BUT not the only way. Have you saved any money to take this risk ? Can you work for say 12-18 months and not worry about paying bills if you quit your high paying job ? If yes, then by all means you should consider it. If you don't have anything saved and you don't live below your means, tough luck. You have to give up somewhere if this is important to you.
Another option is to use your money and buy a small project/business that has some cashflow coming in already. This may not be a hockey stick high growth startup but may be you don't need/want that ?