[Retr0id]

As far as I can tell, it's mostly just cost of labour vs cost of buying a new device.

Watching professional repair shop youtube channels is one way to get a feel for the economics of it - it's usually only worth their time if it's a quick fix on an expensive product or a complex data-recovery attempt where the customer is paying much more than the cost of the device itself, because they value the data on it.

[inigyou]

What if we automated it? Obviously, fully bespoke diagnosis and repair can't be automated (that's what bespoke means), but surely we can have a flying-probe machine that you put a MacBook circuit board into and it runs down the common failure tree by detecting the circuit board model and testing voltages at different points?

[Retr0id]

They have devices pretty close to that, in China. Not fully automated diagnosis, but test jigs that hook up the things that need hooking up, and monitor the things that need monitoring. Search "iPhone test fixture" on aliexpress.