Having appliances that are aware of your energy costs is a good reason. There is a massive potential for savings if your fridge and thermostat know to avoid running as much as possible during the hours of the day when electricity is the most expensive, for example. That reason alone makes smart home stuff worth it for me.
Also, having lights that adjust their color temperature automatically throughout the day works wonders for my sleep. It’s like having a blue light filter for your entire home. And don’t even get me started on how nice it is to have a smart TV. It’s basically Android for your living room, which means that you can install 3rd party apps and block ads without paying a premium. Who needs Netflix when you can just directly stream torrents to your TV?