Can you be specific then? Like, you are aware that you have a 2 week period minimum, and a 6 month period for defective wares. There's also many shops that have more than a 2 week period because it's good customer policy. It's not just Zalando, I checked the next biggest German store (Otto) and they have a 30 day free return policy.

By contrast, in the US it all depends on store policy and, apparently, luck. I had some pretty bad customer experiences in the US, and there was nothing I could do then.

For example, this whole Saga on GamersNexus (check other videos) is a good indicator that the US system may not be perfect https://www.youtube.com/watch?v=2fnXsmXzphI

As Steve says in the video, in the US you have no recourse. There's no law. The shop in question didn't feel like being "nice" and the person is out of 500$. For Steve, this amounts to a scam, but the burden of proof is on him. For specifically this reason, the EU has a law that says otherwise.

Just to check, the parent was talking about online purchases but did you mean physical retail? There you indeed have no legal right for a return, all sales are final as you had a chance to inspect the wares before the purchase.

In practice some stores do accept returns if you have a receipt, but personally I have never done that, didn't know it was even an option before an expat was asking about this online. The default is to sell forward in online second hand marketplaces. Especially gifts you receive, those are never returned (as apparently happens in the US said that expat).