A border router does not provide internet connectivity.
A border router is used to bridge e.g. Thread networks onto a regular IP network so that your non-Thread smartphone can talk to it, and so Matter devices on different network types can link up directly if you want a Thread switch to control a WiFi light for example.
Matter devices use link-local IPv6 addresses and cannot route packets onto the internet even if they wanted to.
A border router is used to bridge e.g. Thread networks onto a regular IP network so that your non-Thread smartphone can talk to it, and so Matter devices on different network types can link up directly if you want a Thread switch to control a WiFi light for example.
Matter devices use link-local IPv6 addresses and cannot route packets onto the internet even if they wanted to.