TV to internet is a way, way bigger change than radio to TV.
TV is pretty much just radio with visuals. Both are linear, non-interactive mediums for broadcasting entertainment and information. TV is a bigger time suck, but it's not that different, not in comparison to how completely different the internet is.
The internet is different in kind. It's interactive. It's global. You can be the star of the show. You can silo into whatever little corner of the internet (or web 1.0 chatbort) you want to.
Think of this hypothetical: how different is a society with radio from one with radio and TV? Now think of the difference adding the internet to the mix makes.