> We each have a choice.

You really don't though. You can either pay more, or go to another supermarket with a similar scheme. Doesn't really seem cricket, am I really loyal for buying bread or cheese because I needed them and this supermarket is in my neighborhood?

I don't know where you are in the world, but in the UK it is really common to have multiple supermarkets in spitting distance of each other. Most of them deliver if you're not in the neighbourhood. And not all of them offer loyalty schemes.

GDPR is great and all, but it only takes one rogue employee. I speak as someone who had their data sold by a rogue Aviva employee to scammers all over the world. Which made my life hell for several years.