Issue was: Providers give out crappy routers that are remotely managed and define it as the end of their network, so you can't remove it, because you don't have the login data it uses to talk to the provider network.

The "endpoint" of the provider's network is now defined as the passive connector at the end of the cable, and providers are required to give their customers all information necessary to configure a connected device, so the customer can choose freely among compatible routers, run non-standard firmware, ...