The usage of these school payment systems pre-dates the current Pandemic by some years (the schools my children go to, started using these systems 3 years ago)! So there isn't really any conspiracy regarding cashless being a method of "control" during the pandemic (starting to get tiring now!) or a means to close local business (why would a school do that anyway??); on the contrary the local sweet shop here is still alive and well!!
Even though parents no longer give their little darlings any dinner money it doesn't stop children from spending their pocket money in the local area.
As a parent it is convenient means to admin and monitor all school activity (I get notices, progress and other relevant teacher/parent comms)...plus pay for stuff like school trips (not there's been much of that recently) and lunches; meaning that these are pre-ordered and paid for in advance, so my kiddies can eat without the arse ache of forgetting their dinner money, the catering company can also effectively plan ahead to reduce food wastage.