It seems like quite the hassle to have to pull out one's phone every time one enters or leaves a room just to turn on lights?

Let's hope you don't have to get to the bathroom quickly late at night...

As a another comment said, the smarter way to have a smart light is to replace the switch with a smart one or even better put a relay behind the existing dumb switch to smartify the switch. For me it's important to have a manual override; you shouldn't need an app for a thing as basic as turning the lights on.

Disabling the physical light switch should usually only come after setting up a different way of controlling the light by hand, without a phone.

Most likely there is some sort of motion or presence sensor that turns on the lights which then turn themselves off after some time or no more presence is detected. There are also small wireless switches that could be used in place of the actual wall switch.

I have done so in my apartment for example. Since the bedroom light switch is for some reason outside of the room I taped it down and put a wireless switch in a more reasonable spot. Another example is the hallway light, which only turns on by motion sensing when the sun is starting to go down.