The only concern I have is the experience they are earning. In a "traditional" summer job (car wash, manual labor, cashier, etc.), you gained experience in something I'd call "grit" - harsh work conditions, people yelling at you, etc.
Being an Instagram model or YouTuber still deals with its share of internet trolls, but are people learning to handle when things "won't go their way"? I don't think that's the term I'm looking for, but just the overall "not enjoying the work" part of, well... work!
My concerns are because people are failure-averse, we hate negativity. A YouTuber/Instragammer can simply not read the comments, or selectively filter the comments. Are they getting the same "grit" experience as the more traditional work environments I mentioned above?
EDIT: As you'll see in my responses to comments - what about non-person "grit"? Does being an Instragram model or YouTuber develop the grit to push through the annoying/boring/tedious/stressful parts of making money? When you a digging ditches, you don't exactly get to "ignore" the negative parts of the job. When learning, you don't get to "ignore" the struggle of not understanding something. Grit or perseverance (pick which one you like better), is a necessary skill that more physical jobs teach. Being the center of some social network clique, does not.