Some people do do that. Try stepping outside of your bubble.

The average hourly wage in the United States is $30, so 15 hours a week is $450 pre-tax. Live on that with a family.

If you don't think that there aren't people doing that already in this country, get out of your bubble. How much do you think farmers are making?

Farmers (i.e., Farmers, Ranchers, and Other Agricultural Managers) make a lot more than $450 a week. Average salary for these folks is $70k/yr.

A farm hand only makes like $15/hr on average, which puts it on par with a job at McDonalds or such.

I think people are doing it and I think it sucks. If you are making $10 an hour in the US you aren't really making ends meet.

I concur. They're not looking in the right places. Musicians and artists would know about these sorts of hustles, but not your typical HN bubble dweller.

I know at least a dozen artists, and not one of them has found a side hustle that lucrative.

Instead, they get a Master's degree, and use it teach at 2 universities, and work a third job part time so they can afford rent.

There's a youtuber I've seen who I think is mostly legit who spent not much money on land in the middle of nowhere and built himself a one-room cabin and an outhouse on it. He's up-front that he isn't actually living off the grid or even in the cabin full-time, but his point is that if you live a very modest life and are handy, you can live on just a side hustle. Like you said, you're unlikely to meet people like this in the (sub) urban tech bubble.