Sure, I could do that, but not everyone can. But you still have the problem that many of these devices don’t function well unless they can phone home; they don’t very firmware upgrades, and they expect to be controlled by a bespoke app. If you filter out all the devices that are HA compatible without running through an external service, you shear the product choices in half.
What? I had to uninstall Factorio to install Space Age on my machine (Linux) - I’m pretty sure I see new stuff in the tree, although I’m still building from scratch in the rare time I get to play.
I sure hope I don’t have to install mods! I’m trying to keep this play clean.