Like someone else said, it’s a hobby. I spend money on things, they make me happy for a little bit, they make problems for me, rinse, repeat.
Why do people go fishing when you can buy fish in the store? Why do people draw instead of taking pictures?
It’s nice to go to bed with all the lights on, press a button and have them all go off. It’s nice to have the doors lock when I leave and unlock when I come home. It’s nice to get an alert on my phone if my garage door is open when I leave. It’s nice that all the lights come on as the sun sets.
None of these are necessary, but all of them are nice and it would be annoying if I had to go back to dumb lights.