I'm going against the popular answers, so here goes:
He can use the rich online job to buy the things like a house (if he doesn't have one already), save enough for real estate, start a business etc.
when he is at the top, those same friends with the “proper” jobs will be envious.
Because a lot of people are in proper jobs and are unhappy and still struggling to make ends meet.
Once money is not an issue, he can always find a job if he wants or re-train.
Importantly, what makes him happy? Would he be fine working for less than his current income in a proper job?
Is there a proper job he can do which will pay him the same or more than his current income?
If his main priority is a proper job, and money is not an issue, he can re-train in an another area. For eg. IT, law, teaching.
Ultimately, it depends on what's important to him currently and what makes him happy.