The problem Apple and an awful lot of other brands have (had) with Amazon, eBay and other stores allowing third-party sellers for their products is that there are an awful lot of scammers around - Apple literally had to build a fake detector for AirPods into iOS [1] because the problem got so out of hand. And yes, obviously they have to deal with a lot of people expecting actual AirPods or other Apple hardware who got fakes and contacted the original brand for support.

It's sad to say but unfortunately I don't see a way out of this mess than strict brand control measures.

[1] https://www.macrumors.com/2022/09/12/iphone-fake-airpods-ale...