It makes sense if you've got a big family or you're always forgetting to close the door properly - then notifications on your phone actually come in handy. Otherwise it's more convenience for lazy people than something you actually need.
I know people who had a fridge with an app, they checked the notifications for like two months and then just stopped caring and used it like a regular fridge. But when their freezer broke in the middle of the night while they were on a business trip, he could check what was going on without calling the neighbor. But that's a pretty specific situation. Usually you end up paying decent money for Wi-Fi, and only a handful of people actually see real benefit from it.