Does pairing (or network joining or whatever it's called) work in Matter? Or is this going to be like Bluetooth where 30 years later the most fundamental underlying workflow still finds new and innovative ways to be completely broken for the most basic tasks?
Pairing mostly works. Matter is still "new", despite having been in the cooker for a few years, and there are glitches to the setup process, but it works eventually.
I've got a few cheap Matter light bulbs that I've picked up mostly just to play with, starting a few months ago.
This fleet has several random and forgettable names on the packaging and exactly two (also unmemorable) manufacturers so far.
Pairing is a little weird: It seems to broadly involve a pocket supercomputer with Alexa or Google Home or Home Assistant or whatever, and scanning a QR code.
This QR apparently begins Bluetooth handshake between the light bulb and the pocket computer, wherein things like WiFi information seem to be exchanged.
After that, Matter devices (in my application at least) just live on WiFi.
This all happens without needing weird(er) apps, overseas clown accounts, or manufacturer-specific hardware. It is local. (Well, Home Assistant is local. The others...are whatever hybrids they are.)
And multiple local control systems (like the three I've already mentioned) can each monitor and control each Matter devices directly. There's probably a limit, but it's nice to have these things non-interactively interacting. ;)
And they seem to be working fine. Boring, even. Right now I just have all of my IoT stuff on the same VLAN/SSID as everything else because it is easy, but I have 100% confidence that these Matter devices would continue to boringly Just Work if I were to isolate them to their own VLAN with zero WAN access.
(Maybe that's something I will work on when setting everything up again after the next move.)