As a counterfactual the other hand everyone in China appears to pay by mobile phone without problems using WeChat Pay and Alipay and no one seems to be locked out. Almost no one I know carries cash - it's just for the tourists who can't access that system. In Africa, mobile payments seems to have driven financial inclusion rather than the reverse.
The cashless economy certainly drives de-anonymization, but very little evidence of "locking out poor" exists where this has actually happened
The cashless economy certainly drives de-anonymization, but very little evidence of "locking out poor" exists where this has actually happened