Not sure about the rest of the world, but I would say that the US is an outlier when it comes to return policies.
A return period is even mandated by law in most advanced countries by consumer protection laws. The length varies and sometimes there are some exceptions like software and customized (engraved products).
> Many retailers, as part of their business models, allow returns if customers change their minds or receive unwanted items as gifts. While many retailers have decided this makes for the best business practice, they aren't legally required to accept returns. Rather, retailers are required to accept returns only if the sold good is defective or if they otherwise break the sales contract. [1]
[1] https://consumer.findlaw.com/consumer-transactions/customer-...
Returning used anything in US is cultural courtesy.
Returning in EU is mandated by law, but for online purchases only and unused products, with hygienic exclusions - the purpose being giving you the same chance as in a brick store to see the product. Opening the box, returning, sure. Using for a week, putting it in your ears, then returning, nope.
Apple Store policy varies by country slightly, but generally they allow 14 days unconditional return. That’s rather unique, and entirely voluntary, and Apple Premium Resellers rarely (never around here) have the same policy.
In many parts of the world there are consumer rights which guarantees the ability to return items even if opened.