C'mon Mozilla, please. Less projects that will end up like Firefox OS, more work on _Firefox_.
It did not lead to widespread Firefox mobiles, but it was not wasted work.
The real thing that kills this is that there's no native support from Google Home or Alexa. They're easily the best way to control IoT devices.
But since you pointed out a necessity, and for every necessity there is a customer, one can start a SaaS for (Mozilla) gateways, charging for traffic/storage.
There are others IoT providers, but I think there is none for Mozilla's (?).