A little true background on Insteon
Insteon has been around for a looonnng time, since well before anyone thought of IoT. I'm sorry that they have gone under, the loss of their server for the Insteon Hub is only a minor impediment. Most people who have used Insteon devices have also used one of the non-web dependent hubs or computer software, though the devices were able to communicate and control each other without that, and certainly without the web (though it is nice to have that available to use VPN back to an intelligent hub/controller).
It is a powerline technology, like X10 was, but they also later implemented radio link as well, and unlike X10, had 2-way communication, instead of merely hoping that a command had been received. Most home automation wireless systems piggyback on the wifi bands, where wifi, bluetooth, microwave ovens, cordless phones, and too many other devices stomp all over each other. I forget what frequency Insteon used, but it isn't the wifi bands as I recall.
Hopefully the new owner will continue production and/or release sufficient information for others to produce the devices (Insteon only allowed a few other companies to produce devices, and I think then only with modules purchased from them). Configuration can be complex, but real applications of anything often are. So there is a lot to criticize them for, but IoT isn't really it.