Neither a laptop, the data is in the harddrive, you can protect the drive encryption without putting software checks so if I put a "unauthorized" component the thing won't work anymore.

A car also starts at $15k, so a windshield being half the cost of a car is not reasonable, whereas a new screen plus labor being 1/5th the cost of a phone is.

A simple example, there are 2 old Macbooks, no warrenty, one has the screen broken one the motherboard, Apple will not sell me a screen, maybe there are no more screens or if they want to sell me the screen and replace it, it could cost me half of a new laptop .

I could use the good screen from the broken laptop and give a few more years to this old laptop instead of throwing the good components to the bin. Third party repair shops have salvaged this components and they will install them to the customers, everyone wins except Apple who is not selling a new laptop or a new screen+services.

This issue happened with iPhones where changing a button bricked the phone a few months later when Apple did an update, the excuse was security but it was only an excuse, you could keep the security too, worse case scenario wipe the data but don't force people to throw old hardware because is too expensive or impossible to repair.