I did not suggest they switched to card because of the pandemic. I was saying the obvious alternative is currently frowned upon because of the pandemic. So I reject your "tiring" comment.
Re last paragraph: what happens if the child forgets their card? Or the parents forget to top it up? I used to work somewhere that had a fancy card system for paying in the work canteen. It seemed all futuristic at the time and cool... until they stopped accepting cash. Trying to buy lunch and finding the card was 10p short was a major pain. Leave your lunch getting cold at the till, go out to the corridor, wait in a queue to get to one of the machines, feed cash or a bank card into the machine to top up the canteen card, go back and pay for a now cold lunch. A major ball ache. I'm trying to imagine the equivalent where I don't even have the ability to top up because I'm a kid without my own money. It would really suck. And asking a friend to lend me a pound ain't gonna work either.