There’s no need to use Insteons hub/cloud service. Most Insteon power users that I know are using homeseer, homeassistant as a way to control the devices.

The other good thing about, at least the light switches (which is their core product), is that they work without an internet connection and will continue to function.

However unfortunately the less tech savvy users who set up automations through Insteons service will be left (quite literally) in the dark now.