It's overcomplicated because it's not immediately easy to keep the smart functionality totally local to your own network.
Almost every company that sells an IoT product wants you to make online accounts, download their special app, sign up for subscriptions, download useless firmware updates, and have all the hardware connect externally with their mothership cloud servers in order to function, all because they want to run a data harvesting racket disguised as an "ecosystem".
I'd use mechanical switches in the house, but at the same time, yelling at Siri to turn on my lights for the third time is the closest thing we currently have to sexbot servants. I only have so many years left on this planet, and I wish to embrace the future now.