My entire “smart” home setup is built with Matter over Thread. It’s fully local. No internet access required. With Home Assistant onboarding can be done without a smartphone now. Devices without official certification work but probably only in Home Assistant.

Dunno, personally I have found HA + MoT to be strictly worse than Z2M. It's the classic case of the Douglas Adams quote:

“The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair."

HA MoT has a simplified UI, that hides hellish complexity underneath, that's held together by loose pieces of gum, which means its difficult to troubleshoot. HA has a rather laissez faire policy to stability, for example, they rolled out an update just recently that made it impossible to add new devices.

I just readded yday evening my Ikea temp sensors as they mysteriously stopped working for no reason. Why? Who knows, but you can't ship stuff like this to a non-technical audience, especially if they rely on it. I had it connected as the temp sensor of my AC, and was surprised to find the AC was not working, thats how I found out it suicided itself.

My Matter over Thread stuff keeps occasionally falling over in Home Assistant and becoming unavailable, probably a router issue as I’m using a homepod mini but still endlessly frustrating.