I feel like the biggest problem I've had with smart home technology is that there is no out of the box standard for controlling or having access to all of your devices. Almost every device seems to require interacting with it with the vendor's own app or other utility, and so I've needed to install a multitude of at least 3 apps just to control the lights. So not only are vendors trying to compete with their smart devices, but additionally with the apps they've created to even use them, probably to see how much more money they can squeeze out of selling your personal information.
Thankfully, there's Home Assistant[1], which is an amazing project that aims to bridge connectivity and control between all of these devices into a single centralized environment. Pair that up with Tasmota[2]-compatible devices and you can have a smart home that can be completely disconnected from the cloud and in your control.