Regardless of whether or not you do the repairs yourself, you reap the benefits of the design as some combination of longer life, lower repair bills, and higher resale value.

Apple's pricing for a battery replacement - which I've never needed, and I tend to keep my devices for about three years - is about the same as the price of a new battery from a third-party vendor, and it comes from installation. I've had to replace two screens, and Apple's price is the same as the mall kiosk - and it'll be first-party parts, maintain the warranty, and my fingerprint sensor will still work right.

Apple devices (both laptops and phones) have a dramatically higher resale value than others, so that bit of your argument baffles me.

I was talking about your car.

The reason why apple offers those services is because it has competition. If they figure out how to make third party repair intractable, you can expect a full reversion to the "screw you, buy a new device" state of affairs.