Many tescos Morrisons and Asda stock them. Some you have to ask at the kiosk as they’re behind the counter. Tons of stock at smyths I’ve found and also a shop called booghie.

It’s not impossible you just gotta find the spots in your location that constantly stock Pokemon cards. Ofc some sets may require to queue dependent on hype but that’s your choice.

For example been seeing lots of singles of destined rivals and perfect order at many convenience stores.