BS, you can train people to do in any job: actor, acrobat, adult actress, assassin, astronaut... zerg-destroyer and zoologist. You can absolutely train likeability and maybe even luck. In fact, plenty, of models on this forum have trained other girls on how to be cam models, and the teach them things like how to increase their likability such as thanking tippers. Yes, there are other sources of information, which if you got good internet skills, and are fluent in English, you can access. But plenty of folks don't have either. I think because of stigma and newness there are lot less resources for learning how to be cam models than most other jobs. If all that information was easy to find as you say, how come so many new models, post on this forum, "I tried looking on the internet, but I had no idea what I was doing when I first started"?
There is plenty of information on how to any job on the internet, and yet for some mysterious reason, most companies spend a lot of money, using live humans to train new employees, instead of just saying "have questions, Google it. Either they are wasting a ton of money, or they found that some people learned better with live or one-one instruction.
There is no question that camming isn't easy and not everybody can do it. But the universe of potentially high-paying jobs that are also easy to is pretty much zero. There lot of jobs that I'd be awful at, as well I discovered a number of jobs that I turned out to be pretty good at, but if you had asked me at age 19 or 20, which ones I'd be good and bad at I'd have gotten a lot wrong. Lots of reasons camgirls, but I'm sure plenty quit because nobody ever told them what they were doing wrong.