One friend who has kids is a teacher. His ex was a school administrator. Now that they are divorced, he'll take the kids for one month in the summer, and she'll take them for the other.

Another is currently working on outfitting his camper van to be family-ready, plus building out a trailer to function as a home office. He works as a therapist while his wife works remotely for a nonprofit.

Another friend just had a daughter out of wedlock irresponsibly young, and now just does odd jobs under the table in his 40s when he wants money.

Friends with home bases do a number of things. Some rent them out - this is easier if you hire a management company or have someone nearby to help out if things go wrong. Some actually do make enough money to just leave them sitting there for a while. One friend has a "home base" that is literally his friends well water pump shed. A few friends have raw land that they park their vans on, which they are constructing more permanent homes on at their own schedule.

Passive income streams for everyone I know of are landlording or index funds. This is what I personally do. I have two properties - one is a big house in the city where I rent by the room. The other is a mountain cabin vacation rental. I do pretty much all the maintenance and management of these places myself. Just today I was pulling weeds in the gravel driveway, and the next time I have a gap in guests I'll be restocking the soap and coffee and TP at the cabin. This summer I'll be getting dirty and sweaty doing fire mitigation and landscaping. You can say it's a grift, but all I see is that I'm offering affordable rent to people who recently moved to my city, often giving them a community in the process; and then helping families enjoy the beautiful mountains when they have a week or a weekend of vacation off. Of course, I am profiting simply from the fact that I bought the land at a particular time - for more on that, I'd recommend reading about Georgism, the most fair and efficient taxation scheme you've never heard of. But at the end of the day, the system is what it is, and I'm unlikely to change it. So why leave the opportunities around me just sitting there (where someone else will scoop them up anyway) out of some kind of impotent moral outrage?