Seriously? IoT is a quickly growing, potentially massive and ubiquitous field. Given the shit state of security and technical implementation of its initial era, in very glad that a well-resourced non-profit is helping to create an open standard.
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 (?).