I agree, at this time, you cannot use bitcoin for paying groceries and other small stuff that needs instant payment. It is preferrably used for big transactions like trading and investments. Since bitcoin is volatile, it is more advisable if you invest bitcoin.
yes bitcoin wasnt used to pay groceries etc instead people use it to buy a large amount of sums or small , trade or sell it other used it too to hold bitcoin and waiting for the price to increase but it can still be used if the store decides to use bitcoin as payment if transaction fee wouldnt cost alot