A good cashier can process cash sometimes quicker than even the fastest card readers I've seen, and not all card readers are nearly that fast. A lot of them are

A good cashier can process cash sometimes quicker than even the fastest card readers I've seen, and not all card readers are nearly that fast. A lot of them are slow, painfully so. If you have to sign, that's also slow, another step in the transaction. What it works out to be is that sometimes it's better to use card and sometimes it is better to use cash if speed is a factor. Someone that takes too long because they are fumbling for cash are just as likely to be the type of person that would have to fumble around for their card or have other issues operating the terminal. Cash is quick and painless with only the most minimal amount of mental arithmetic necessary to give someone their change, not that your typical register won't spit it back out at you anyway. If it is a sit down restaurant with table service though, there's no real positives or negatives to using either besides whatever is most convenient for you. So all in all, all I see in any push to go cashless is the illusion of progress. It's all theater and it is strictly speaking, completely unnecessary to go cashless with considerable downsides if society is forced to.