I have found that (so far) it isn't possible to use cryptocurrency to buy groceries, without involving either a bank account, a smart device, or both. I use a computer with wired ethernet connection to access the internet (like it's 1999!), and I am concerned with privacy. I'm unbanked (I can't/won't use banks) and will not use a smart or wifi-connected device. My research, and in asking several knowledgable people for their help, I've found there's no way for people like me to use crypto.

If there's a way to do some of the necessary steps using a semi-anonymous burner flip phone, that's helpful, but not exactly cheap or convenient to enable mass adoption.

Since a large part of what makes crypto crypto (privacy) is not yet convenient, mass adoption will not happen yet.

There has to be a fairly simple way to transfer and convert currencies without betraying one's privacy, or 1 of the 2 main reasons to use cryptos is lost. (At least they are still decentralized if you're using them in conventional privacy-destroying ways.)