A couple of days ago at lunch I bought a Coke Zero and really struggled to remove the cap. One of the pieces that holds it on hadn't been perforated and it took a serious yank to finally pull it loose.
Meh. Bad luck. But later in the day I bought a carton of milk. When I opened it the next morning the same thing happened, and I yanked the cap so hard I splashed milk all over the room.
The next day I bought a bottle of water and it happened again. This time I was finally savvy enough to realize it was intentional—though I couldn't fathom the reason. Then, by chance, the Wall Street Journal explained everything:
In 2021, [Coca-Cola] introduced a design that connected some of its plastic bottles to their caps as a test in Germany and Spain and subsequently expanded it to other European markets. The change helps more caps get recycled with their bottles rather than thrown in the trash or on the ground, the company said. It also complies with a European Union directive set to take effect this summer, which has pushed Coke’s rivals to follow suit.
So that's the answer. Apparently people were tossing empty plastic bottles in the recycle bin but throwing away the caps in the trash. The new EU rules keep the caps attached, so the whole thing goes into the recycling bin.
Is it worth it? I suppose, though it really is a bit of a pain at first. After a few days, though, you get used to the cap brushing your cheek as you drink. Nevertheless, in America I'm sure it would provoke a whole series of congressional hearings from Republicans opposed to woke water bottles or something.