Flexibility. A hardwired switch is choosing your lighting configuration at build time, but when you have light bulbs that can all be controlled individually through software, then you want a switch that can interact with that software.

For instance, let’s say you do something crazy and unprecedented like add a lamp to your room, with hardwired switches now you either have two switchs in two different spots to deal with every time you enter a room, or you need to call an electrician to wire up a switched plug. If your switch was instead a software switch you could just reprogram it to also control the lamp.