I am not totally sure about national currencies but threat in job is absolutely possible to happen. Actually it is happening right now in the current scenario. I've known a lot of people who left their regular job coz they are already earning so much money here compare to how much they earned on their job.
I also quit my job to invest in Bitcoin. As far as I'm concerned, investing in Bitcoin is a lightweight and time-consuming job, but it can make a lot of money every month. If Bitcoin is more popular, then I believe there will be more people quit the job and investing in Bitcoin-like me.