IOT is a fail because of manufacturers.
For example, ZigBee connected light bulbs, GE Link, Cree Connected, and Phillips Hue all use their OWN modified protocol. First the use the ZLL protocol instead of the ZHA that they should be using, then they refuse to repeat signals for other brands. So you have some cheap Cree bulbs in entryways and hallways, but have the expensive white color temperature bulbs for elsewhere... Oh they don't mesh, sorry. They also don't mesh with your other devices so you have a horribly broken and fractured mess that barely works.
IoT is an epic fail because we don't have a group of people going to different manufacturers with a sack of rocks and beating the shit out of executives and head engineers. I blame ZigBee and Z-Wave for not forcing companies at gunpoint to follow a freaking standard, but the engineers and executives made the decision to be assholes and intentionally be incompatible.