Dieter Rams' style of industrial design has just dominated influencing electronic product design. More expressive industrial design at large isn't dead. Even in the electronics adjacent spaces you have boutique companies making interesting industrial designs for things like synths or computer keyboards.

Though I think there's another perspective to entertain here that isn't just about the industrial design style of the phone or display. Instead, think about how many discrete products general computing devices have subsumed. The disappointment comes across to me less that a slab is consumer computers dominate form, it's that the slab has made the rest of environment more sparse and now a slab is the sole focus point.