The third-party repair industry exists because companies can profitably undercut Apple's out-of-warranty repair charges. That's true in the US and it's doubly true in lower-wage economies.

It may be that skilled repair work isn't scaleable, so Apple have decided to constrain their repair operations to simple module swaps. It may also be that Apple would rather sell you a new device than fix your old one, so have taken an approach that is broadly hostile to repair. I suspect it's a bit of both.