This doesn't make sense. I have sold every single iPhone that I have owned (about 6), and virtually all were 100% functional at time of sale. Making the products openable will likely to make them heavier, more expensive, larger, and more prone to damage (i.e., water damage), and thus less durable overall. I don't want this as a consumer as it will lead to more waste.
Not sure how your personal anecdote comes into play. So you have replaced your phone every 2 years while it's still working, good for you. But have you considered that some people will replace their phone only when it's broken beyond repair?
Apple's approach still makes sense in that scenario since the phones in general will be easier to make more durable. There are far many more phones that are exposed to water than there are people who regularly repair/upgrade their phones. Openable phones are going to be nearly impossible to waterproof, or will make them far larger and more expensive.
