The reason why this product exists is for homes in places where there is no telephone or cable tv wiring to the house.
This is a massive part of the world and part of why the countries that didn’t have a wired setup in many cars jumped straight to wireless.
Making something intentionally significantly worse to save pennies on the BOM is not something that should ever be defended.
If it has a cellular internet connection there's no good reason to not at least also have WiFi, and if it's the kind of device that isn't expected to be moving around while in use there's no good reason to not also have ethernet.