Shopping carts are always broken because the store doesn't give damn. For instance in my current city giant Auchan store has literally every single cart busted, unmaintained and completely rusted top to bottom. Similarly sized Carrefour has normal carts, mostly without any issues, just like Ikea and several other medium and small stores. Kaufland even has some fancy new carts, which not only work fine but have some modern ergo handles. It's just some Auchan middle manager has decided that they aren't interested in the carts and that was the result. And adding more insult to the injury - those Auchan carts have fully indoor use, because parking is inside same building, and Carrefour and Ikea have open parking lots with carts experiencing weather and rough pavement.
We can try to blame weather, people, stack problem, ethics, cart design, economic downturns or taxes, but that's all a misdirection. The blame lies squarely on some middle manager who either enforces maintaining and replacement of the carts or he doesn't.