The upside of checking some luggage is that, if you get stuck in security of whatever, the plane cannot leave until they’ve found and unloaded your bags, so you get a somewhat better chance of making the flight. Waiting five minutes for you to arrive is better than the cost and time of unloading the hold which might cost them their take-off slot entirely.
There were real devices on sale for a while a few years back. Then the air safety people insisted that the batteries had to be removable during flight, which rather killed the whole concept stone dead.
Card skimmers don’t work with modern contactless and chip-and-pin systems as used in most of the world. In many countries, the magnetic strip is blank or absent these days. The chip authenticates a single transaction, so there is no data to steal from the card.
When I go in grocery stores, there is very little cash passing hands. It’s all contactless or card payments. Not just in Europe and the UK, it was the same in Brazil last month. The world has moved on, probably pushed by Covid fears of contaminated money.
A few weeks ago in Switzerland I needed a surgical dressing changed and couldn’t manage it myself. I went to the local minor-injuries clinic near my home. A nurse did the job and didn’t even want to know my name or see my insurance card, though Switzerland is also an insurance-based system.
Years ago I got a VIP visit (not the tourist one) to the Warner Bros backlot, including visiting their (huge) Wardrobe store. We were told that on Oscars night, while the women usually get new fancy designer dresses, many of the men will borrow or rent a suit from one of the studio Wardrobe departments. Some of those suits date back to the 1930s, but are lovingly kept for use in period productions. They have tens of thousands of outfits in storage. Honestly, the one at Warner was like a vast warehouse of clothes, all carefully indexed.
The upside of checking some luggage is that, if you get stuck in security of whatever, the plane cannot leave until they’ve found and unloaded your bags, so you get a somewhat better chance of making the flight. Waiting five minutes for you to arrive is better than the cost and time of unloading the hold which might cost them their take-off slot entirely.