I’m not so sure. It’s a really small push but people from places where it exists only in some places and where in others they don’t return the carts it seems to be working. Here they are returned, but we are so used to the coin system that it might be leftover from that. Anecdotally I’ve noticed people leaving them wherever more if there’s no coin system. But also my area has a lot of first generation and very recent immigrants so they might’ve never been with the system to begin with. Or it’s a cultural thing. Dunno. Might be all the reasons.
I’ve seen a lot of places here drop this system. I have no idea why. Then again, you could also just go to the info and get a plastic thing to unlock them.