While they are called crypto currencies, most of them if not all aren't used as currencies.
I just to give a hint I am involved since 2011 and just dumped all crypto. When I get crypto tips from strangers at my son's swimming team, it's about time to quit it.
You can achieve this any number of ways and it has nothing to do with currency or money. FYI Gold, which you can buy a million different ways.
But since prices are crazy volatile, and it could be worth $0 tomorrow, it can't be used as currency, and it makes a terrible store of value.
For every 'practical reason' to use a crypto, there are already many other better solutions.
The only 'real reason' people buy them is because they want to make money flipping it and that's it.
Now that inflation is up again, people are realizing that fact. Gold is going up, Bitcoin is going down.