Depends on how you define it. I knew a couple of guys who just grew up and did a boot camp and got programmer jobs, or took a job with their parent or friend of parents company. Also a few women, and one guy, who just married a wealthy spouse so they could continue to be moochers forever. One or two had their parents move out and give them the house while they did low-wage work.

I have never known anyone of the 'basement dweller' variety though, these are all wealthy folks from wealthy families who had tons of social connections. I met them in college/graduate school.

Also knew a couple of people who just never had a job and lived on poverty-income but from their inherited stock returns. They were into speed running games..