Personally, I do not own a printer. If the 20 dollar Amazon Basics backpack I buy requires me to metro to a library, print a shipping label, find or buy a box to send it back in, then walk to a post office, that can be 1-2 hours of lost productivity - often more opportunity cost than the item itself cost.
Now if something isn't urgent, I'm more likely to just go to a CVS or Walgreens - at least if the item fails I can return it.
Finding a box can be troublesome but I think this can be mitigated by saving whatever box you receive your item in until you're fairly certain you won't be returning said item.
All in all, I can't think of a more ideal return system. If you've ever tried returning something to other online merchants (e.g. Newegg, TigerDirect), you'd know that Amazon has the best solution.
[0]https://www.amazon.com/gp/help/customer/display.html?nodeId=...
That long-term thinking has let them get so far ahead of their competitors that even with experience quality declining, I'm sure they'll still do well for quite a while.
That, alas, is the natural outcome of a metrics-driven management style. If you use short-term measures and see revenue increases as good, then you inevitably stop seeing your customers as people; human relationships are subtle and long term.
For a long time no competitor could have gotten my interest, because I trusted Amazon. But now I'd be willing to switch.