Insteon predates internet connected devices. Their protocol is not cloud based. It isn't even hub based, you can pair switches to outlets directly. The hubs

Insteon predates internet connected devices. Their protocol is not cloud based. It isn't even hub based, you can pair switches to outlets directly. The hubs try to connect to the cloud but work locally and have a locally accessible API, credentials printed on the bottom. Their Apps relay through the cloud however to avoid the hassle of local network discovery. So the Apps are completely useless now. Most/all devices and the hub have a pairing button. You can pair devices to each other or the hub still. It's complicated but works, the App also coordinated pairing and was easier but still kinda janky compared to competitors. Home Assistant can talk to the hub via it's local API and still manage and paired devices. 3rd party hubs like Isy still work just fine. Because Insteon is no longer making devices, they are now selling for a premium on eBay because people invested in the ecosystem don't need to change. People like my mom, who only has a hub is 3 devices, are better off selling for profit now and jumping to a new platform. Those using Isy can just keep going as Insteon devices are well made and will continue to function for years or decades.