In that case it would probably affect water resistance.
For a while companies like Motorola were selling nano-repellent (essentially hydrophobic) coating phones and calling them splash proof. You could easily design a gasket or something, existing waterproof phones already have parts that open for eg the sim card or microsd slot (which are gasketed).
If they don't want to, then they can make something less rugged.
No excuses for resource waste and pollution.
Making sure something survives splashes or a minute at the bottom of the swimming pool will be enough to keep most of these things working.