Are you talking w.r.t. Netherlands, Belgium, or elsewhere?

Europe used to have a fair number of cash only stores for the reason you mention. But Belgium recently changed the law. There are 3 laws on the books now:

1. You must accept cash (per the old still-existing Belgian legal tender law)
2. You must accept at least two forms of payment (new law)
3. Of the forms of payment you accept, one of them must be electronic (new law). Note that “electronic” need not necessarily involve a bank. E.g. cryptocurrency satisfies the compliance.

But Belgium is not enforcing law “1”.