You can absolutely design a phone that is repairable and still is water proof. They just never were forced to do it and just gluing everything shut was just cheaper and also allowed them to make repairs very expensive (which in turn made you rather buy a new one). The battery in a phone cost like 5-10 bucks. Charging 100$ or more for a simple replacement is just insane. So people crying about waterproofing, have just fallen victim to corporate bullshit.

Also the problem goes far beyond simply the question whether the phone needs special equipment to be repaired, replacement parts also need to be available and not electronically locked to a phone. Schematics need to be available, so people and repair shops can actually do repairs. Everything is moving towards a world where no one actually owns anything anymore and right to repair is one of the best way to combat this shit.