I often buy stuff from an online shop that solved this issue in an IMO rather good way, for both themselves and the customer.

If you return a product for another than not working, it gets tested and checked for flaws. If it works fine, then it’s resold in the same online shop, with a discount, tagged as an “open box” product. The system is transparent for the customer, you can often buy cheaper goods this way, it doesn’t unnecessarily trash goods, and it cuts out some of their losses associated with the returned product.

I used this system once, to buy my air fryer; the product itself was pristine, and I got no issues. The box had a crumpled corner but hey, my cat didn’t complain about it.

The shop in question specialises on electronics and household appliances. In most cases you can kind of guess why they were returned, inattentive customers buying stuff with the wrong voltage or hardware incompatible with their desktops.