For us who doesn't have enough we can't rely to live from our crypto-income, but there are people who are earn a lot in crypto-currencies, they can sell parts and still have a good life, and savings in crypto-currencies.
Well, you said it yourself. They may sell some of it but they don't rely on it. There are those that earned a lot of profit from cryptos but I don't think they really rely on it. Some people I know is just holding their btcs and cryptos right now and they are not planning to sell them since the price might pump in the near future.
Unless they are working for example, freelancing and taking their payments bitcoin, we can say they can rely on it but I would prefer to accept fiat if that is the case since the volatility of it may affect me.
Well, not all of us wanted to do that unlike you. All of the crypto currencies I can get is being held for the future that if it pump again, I would be able to get some proifits from it. Since I can't really use it here, maybe we can say that people would be relying on it if it is widely used in their country.
Still, I don't think people would be doing that since most people would hold their bitcoins rather than use them especially these days that the price is unpredictable.