There are two ways competitors are incentivized to copy Apple, the first one is because of Apple's mind-share and "fashionable" status, they might be convinced that by copying some of the features they will be able to ride on coattails of Apple's success to get some success of their own. Combined with the fact that purchasing decisions are not entirely rational and there's a lot of emotion involved, Apple and other large corporations are in a position to convince people to accept compromises that have larger effects (sacrifice repairability for slimness, sacrifice freedom for "security", sacrifice gas mileage for a bigger, more comfortable SUV, etc.). The second way is that Apple, by virtue of their mind-share and position as leader, can get away with changes that other companies would want to make but couldn't. If Apple hadn't removed the headphone jack from their iPhones, there's no way Samsung or Google would be able to get away with removing the headphone jack from their flagship phones, even if all three companies want to remove the headphone jack equally, but once Apple moves the overton window, the competitors can jump onboard with the change and implement it into their own product line. Apple has earned themselves enough of a reputation and enough of a fanatical userbase that they're able to get away with these changes because by-and-large their bad changes were balanced out by their good changes, the question is whether this reputation will last for the current Apple.
>Isn't the drop in repairability of electronics being pushed more by the shrinking of components than by the assumption of corporate greed?
Absolutely not. Shrinking components have made it possible to make more integrated ICs, but those were never user serviceable, but replacing a monolithic IC with a spare part, even with unfriendly packages like BGA, is not impossible to do for a decently equipped repair shop, and the cost of that equipment is going to likely be less than whatever car mechanics or small machine shops spend on their equipment.
For what it's worth, I don't think Apple or any other company are sitting in their board rooms wringing their hands and coming up with dastardly plans to fuck over the third-party repair shop. Third-party repair is simply not a priority for them, thus when the time comes to cut costs or to optimize the design for sleekness or profit, repairability goes out the window first. Contrast that with more professional equipment where servicing is an important consideration and you'll see design optimization producing different results.
