Stablecoin Or Coffee with ADA?

I remember in one of the interviews, Charles mentioned, someday someone may offer a stable coin on Cardano blockchain.

Recently, I have seen some group of people developed a coffee machine that accepts ADA as payment in Japan.

Is this a valid use case for ADA?.

Surely any retail transaction would be a valid use, why not?

Use case will start out small, to buy a proverbial coffee with our favorite crypto is awesome, in the next few years the Cardano use case will grow and hopefully we will see coffee trade contracts as a use case for our block chain we love.