It's a philosophical thing, sure. But the EU is taking the approach that businesses should make honest money by selling quality products, not through consumer-hostile practices like inflating the cost of spare parts + labour for fixing stuff.

In the past our family has had several Android phones where the battery was easily replaceable. We even had a couple of Motorolas where the screen was a simple and cheap thing to replace. That seems to be increasingly a thing of the past.

With those phones, I have never once experienced a failure mode related to seams / screws holding the phone together. If it's one thing that's extremely well known technology, it's fasteners and gaskets for consumer products.

The ancients managed to design around replaceable batteries, I don't think these techniques have been entirely lost to time.

My older Samsung Galaxy had an easy clip-off back cover and easily replaceable battery. Nothing related to that ever failed.

Whereas two newer Pixel phones have had issues with the back cover glue coming loose, leading to interior damage.

Given that, the idea that a case that can be opened easily “compromises the shell of the phone” sounds like a weak excuse for some other deficiency or agenda.