I am not mad at the cashier at all. Poor kid was probably paid the bare minimum and had nothing to do with any policy. That is why I didn’t argue with him (plus there were customers behind me, I didn’t want to hold the line). I asked him once, and left immediately after.

Retail workers are already in a shitty job, no point in making it worse

It makes me wonder, when I draw a line in the sand with a clerk, how often they just enter junk data into the system so they can get on with their shift.

Many years ago I worked as a cashier (at Trader Joes no less) and occasionally had to ask customers for this sort of information. I had zero problem just punching in fake data if the customer didn't want to provide it, and sometimes I just went ahead without asking, if the customer was clearly busy with a crazy kid/pet/whatever.

Some cashiers were diligent about the data collection but many, probably most, had a similar approach to mine.

Poisoning data collection is one of the many small positive actions a front-line employee can make without too much risk to their livelihood.

What kind of data? I’ve had stores ask for telephone and said no but that’s about it.