Well the worry is that you spend more money on a part that turns out to be unusable, so you end up with no device and less money.

That seems like a basic consumer protection issue that's mostly already solved in the developed world. When I get my car serviced, it's understood that I will hold the mechanic responsible for everything so they don't even bother trying to put sketchy parts in my car.

yet Prius catalytic convertors are apparently a big market, so much so that it is a regularly stolen item. so someone is buying these parts to install when a car is serviced.

[1] https://www.inquirer.com/business/toyota-prius-catalytic-con...

[2] https://www.msn.com/en-us/autos/news/thieves-target-toyota-p...!

[3] https://www.theguardian.com/money/2020/feb/01/catalytic-conv...

> The thieves make about £300 to £500 from every converter stolen, fenced through scrap metal dealers, with car manufacturers warning that a gap in the Scrap Metal Dealers Act 2013 enables dodgy dealers to buy them without checks required on where they came from.

Catalytic converters are filled with valuable metals (platinum, palladium, among others). They're torn apart and the expensive metals are resold. The cat isn't being put on other peoples cars.

They're not making money by installing the converters into Priuses.

They are making money by selling the platinum inside.

Some counterfeit parts can be worse than waste, they can be dangerous. Like batteries that catch fire and glass that shatters into sharp fragments.

It can also happens to legitimate products (ex: Galaxy Note 7), but these can be traced and recalls can be issued.

>Some counterfeit parts can be worse than waste, they can be dangerous. Like batteries that catch fire and glass that shatters into sharp fragments.

The real issue is not the part, it's the company doing the service. Legitimate service centers will source parts that are high quality - just like any other industry. People still repair cars (including brakes) on their own - to give you one example.

The only bad part is some of these parts are stolen from users. Because the main board on an iPhone is account locked, crime groups will strip the phone down for parts and sell these on eBay to people looking to fix their phones.

This is why I think Apple should account lock all parts on the iPhone and tell the user this but if the original owner unlinks the phone, the parts will work again.

Crime groups stealing iPhones? What planet do you live on?

Apple is the number one creator of e-waste in 2021.

Why else would we still have phone theft and how do these preowned parts end up on eBay? Less skilled people steal them and then list them on eBay as “account locked iPhone” Then more skilled people strip them for parts and will sell just the camera, battery, etc.