it’s illegal for Tesco to have any number of employees watching/monitoring/“tracking” in the store with their own eyes and using those in-store insights to drive better customer experiences?
Watching what is bought is fine, but walking around to do that is useless work, because you have that in the accounting/sales data already.
There is stuff like PayPal and now per company apps, that works the same as on the web: you need to first sign a contract. I would rather that to be cracked done on, but I see that it is difficult, because you can't forbid individual choice. But I think the incentive is that products become cheaper when you opt-in to data collection. This is already forbidden though, you can't combine consent with other benefits, then it isn't free consent anymore. I expect a lawsuit in the next decades.