I guess I'm conflating two concepts, my overall point is that getting a job in high school used to be seen as "getting your foot in the door", one way or another. Like you said, at the very least it got you money/freedom to explore, and you had time to explore. You were seen as someone who was getting their start in the world.
Nowadays the options for standard middle-class success are a lot more constricted. There is much less "freedom" and "exploring" unless you're wealthy, working at McDonalds will just get you an ultimately meaningless amount of money and experience that no one values, while sucking up your time. Even when I was in high school there was no time for "exploration" outside of academics if you wanted a positive outcome. You were either on the AP/honors track and going to college to be a "success", or you had a job/took normal classes and either couldn't afford college or were just coasting into mediocrity. I imagine it's gotten even more stark since I graduated, given prevailing economic circumstances.
I'd say the desire to be an influencer/streamer is also partially the result of that. Sure statistically most influencers/streamers don't make much, but there's at least the potential of freedom/success that doesn't exist with a McDonalds job, directly or indirectly; and the barrier to entry is low. It would be like if everyone's parents bought them a guitar/drum set and there was a social hierarchy based on being a rock star.
If I can be so bold as to link it into larger trends, one thread I've noticed is that in previous generations' countercultures, whether it was the hippies in the 60s/70s or grungy Xers in the 90s, there was an underlying assumption that the American Dream was vanity. That you didn't need all of that stuff and could "drop out", calling someone a "sellout" was a serious insult. You could always find a way to "get by" even if you weren't living large. Because during those times where the income/cost of living disparity wasn't so large, you probably could. Don't worry about prosperity, go become an assistant manager at Staples and spend your time on what really matters! Nowadays economics don't support that, so we have "hustle culture", where you're expected to "grind", and that's the superficially "cool" thing to do. Even if you're just hocking bullshit, make that money! Given the limited options available to high school students, it follows that being an influence/streamer, something they can literally do on their phone, is the only universally attractive objective.