cryptocurrency on mobian/pinephone

[ryo]

Privacy fans using pinephone need a way to pay without apple/google pay or a credit card.

Do people actually use cryptocurrency as currency or just for trading as a commodity?

As said above, Bitcoin is legal tender in El Salvador, and according to expats living there, it's accepted everywhere.
Yes, even at McDonald's where you can get your portion of GMO fake food for some of your Bitcoin.

Ukraine and Brazil have officially announced to make Bitcoin legal tender in their countries as well, and according to rumors a couple of Latin American, Eastern European, and African countries are allegedly (because not officially known yet) planning on doing the same.
Meanwhile, China just banned Bitcoin for the 100th time (without ever unbanning it by the way), EU and the 5 eyes countries have announced to regulate crypto to hell for the 40 billionth time.

So perhaps the answer to your question would be, depends on where you live.

Japan is GREAT about cash perhaps the best in the developed world, but for many users crypto serves not as cash but like a backup bank account(highly volatile) or speculative investment, it was more noticing that we have a CLI for Monero(more private) but most crypto users are not represented.  I am sure bitcoin core could be ported, it was running on a Linux Zaurus SL-5500 in 2009, but it is just one more app some users may want.

And I think that over the next 3 years, Japan will be the only country in the developed world to continue to use cash too.
Some time ago they even announced some new styles for all the paper notes and the 500 yen coin which are set to be in use starting 2024.
When I visited Europe 2 years ago, I couldn't even go to a public toilet because they only accepted domestically issued bank cards, but at least the staff let me in for free because I had no bank card that supported it, and they refused to take the equivelant amount in cash I offered them.

As for crypto, I think this is more because of how little support crypto has in stores both offline and online.
People might use it more like cash if more stores would accept crypto, which they won't until more people start using crypto, which will never happen until more stores start accepting crypto, and so on.
I hold on to primarily Monero, also have a bit of Bitcoin, Dero, and LBRY Credit (which I rather won't count, because it's a bit scammy considering it's designed to be only usable on 1 specific video platform), but to me too it's all more like a savings account which the government can't touch than it is to actually buy things with.