Having bought a few Matter devices now, I have discovered that, in practise, Matter is just as full of vendor extensions as ZigBee, and the quirks ecosystem that allows for interoperability despite vendor extensions is far less mature than with ZigBee.

Maybe this will get better with time, but we're half a decade into the Matter era and the end-user experience is _worse_ than with ZigBee. In that sense, Matter has failed.