For shopping in physical stores, paying with BTC can really be problematic in terms of the time a customer would have to wait to receive the first confirmation if he didn’t pay a fee that would guarantee him confirmation in the next block - but even that means waiting time can be 10 minutes and even up to 50 minutes (which happened to me once when the distance between the blocks was just that long).

This could be solved with the implementation of Lightning Network, but I don't believe it's something the average user can use without difficulty at the moment.

There are some altcoins that have a 0% fee and instant confirmation, so if you really want to pay a coffee/juice with crypto you can always reach for these alternatives - of course they must be supported at the point of sale.