Not USB, but there exist SFP DSL modems, like the Proscend 180-T. They are pricey and difficult to come by, but with something like a Turris Omnia as a host, y

Not USB, but there exist SFP DSL modems, like the Proscend 180-T. They are pricey and difficult to come by, but with something like a Turris Omnia as a host, you _can_ have a single-device modem/router/WiFi AP