I think very few people give up a full time job to handle and survive from crypto transactions. To become a trader it is very important to have some money to survive for a period of time until you start making a profit. Trading is very complex and requires many years of experience to process all the information that will make you a good trader.
Giving up a full-time job for a job that has no assurance isn't practical but it works with a large risk in it. It's hard to support a day trader if there is no capital you can use when you lose a trade. I think it is better as a side job for a full-time workers or some people that don't want to sacrifice any responsibilities. I know some people who become a full-time trader and they know the risk of quitting their job. They gain months after and until now they still continue their daily trades. It's full of risk but the returns are quite amazing.