Theo wrote:

I think Zigbee is interesting because devices themselves can't phone home -
they don't have a route to the internet nor the ability to speak IP (nor the
power budget). So it's good for things that just do their one job, without
ads/malware/surveillance thrown into the mix.

The hubs can and do phone home, but you can use the devices without the
hubs.

Or you can use the hubs purely locally and firewall them from the cloud,
though if you want voice control via smart speaker/phone then you will
require connection to the cloud

I recently came across:
https://www.zigbee2mqtt.io/informati...d_devices.html
which seems quite comprehensive in support for a wide range of devices.

see also mosquitto and node-red, both suitable uses of an rPI

https://mosquitto.org
https://nodered.org

That can then hook into a third party stack that you trust.

https://www.connectedhomeip.com
https://zigbeealliance.org/news_and_articles/connectedhomeIP

It's interesting, but note that the proponents are hardly the most privacy
focused. So remains to be seen whether it's a spyfest or not.

Yes, I'm not amazingly bothered about being able to control lights when
I'm not there, Google have tempted me into at least having a look at
this stuff, by offering me a free Nest Mini Gen2, maybe that'll be a
smart (!) move on their part.