Airwaves are limited resource - especially spectrum suitable for broadcast. Two companies can’t share the same broadcast spectrum.
The Internet is not a limited resource and not owned by the public and licensed to broadcasters. More than one company can lay cable.
Do you really want the government policing what can be said on the internet?
It does already. Section 230 in the US isn't an unlimited get out of jail free card. Other countries have varying amount of policing, with differing levels of success and corruption. Spain, the UK, and China all come to mind here.