Zigby particularly stood out as annoying to me as it includes its own 2.4ghz physical layer stack which uses the same range as WiFI, which is already overcrowded as hell and relies on some CSMA/CA magic to make even the most apartment crowded area of APs function decently.

I mean, there isn't really any other choices for unlicensed consumer use? 5GHz is dedicated to WiFi. The sub-GHz bands would be great, as there isn't a need for much bandwidth, but it's a huge mishmash of frequencies that would require many different SKUs per device: