It is believed that cash helps people budget, as using it means you literally can count the pennies. Paying with a card or crypto currency make spending easy and convenient that sometimes one tends to overspend. Sometimes one might not even know the balance of his account but with cash you are always aware of how much you have.
What do you think?
It's one thing that Dave Ramsey repeats quite a bit, supposedly based on studies, that people spend more when they use cards, because there is less of what is known as friction. From least to most frictionless payment systems are:
Cash
Debit Card.
Credit Card.
And if instead of having to take the card out of the wallet you use the mobile or smartwatch there is even less friction.
Companies know this and that is why, although years ago they were initially more reticent about the new payment systems, they soon realized that people were spending more with them and have been accepting them more and more.