VC here. If you're building a bootstrapped business, then starting as a side project and building up revenue until you can go full time is probably the way to go.
If you're going the venture-backed route, I think there's a misconception that there's no salary or minimal salary at early stages when you're funded, but this is not true. Most founders take a reasonable salary, where reasonably is defined more by your personal needs than anything else. $100k-$150k salaries are pretty common at seed. That's not Google level, but it's not bad. Here's a thread on that: https://twitter.com/lpolovets/status/1365123608905879555
If you're going the venture-backed route, I think there's a misconception that there's no salary or minimal salary at early stages when you're funded, but this is not true. Most founders take a reasonable salary, where reasonably is defined more by your personal needs than anything else. $100k-$150k salaries are pretty common at seed. That's not Google level, but it's not bad. Here's a thread on that: https://twitter.com/lpolovets/status/1365123608905879555