I don't actually beleive that it is possible now, and not because McDonalds doesn't want to accept my Dogecoin, but also because the current financial system won't let me do that. I like this article about crypto salaries, it gives several examples of what drawbacks of living on crypto alone are: https://blockonomi.com/crypto-salary/
I think that it can be interesting for many of us, as I know that we have a lot of people making their living from bounty campaigns only.