I think it's not a good idea to quit our real job, because working with crypto will not guarantee our monthly stable income, and also the unstable. Why should we choose when we can keep our real work, and work part-time crypto, at the same time?
If he is considering the possibility of giving up real work and engaging in crypto full time, maybe he is ready for it. If he thinks that he already has enough knowledge and skills, he can try. If something goes wrong, then at most he will find another job.