There is non-advertising-supported television and (especially) radio. The BBC and other public broadcasters fund themselves with tax or licence fee income. And when you have small children, avoiding the incessant advertising for toys by putting on CBeebies is a godsend. It's also has really good shows, as it turns out.

Radio is easier because radio broadcasting is much cheaper. At least over here there are BBC stations (locally and nationally), and things like student and hospital radio that are run by volunteers and have no or minimal advertising.

I'm not saying these models are better than ad-funded media, but the ubiquity of ads isn't an actual prerequisite of media. There have also been subscription channels without advertising (before cable companies decided to double-dip) and you can imagine other funding models like television-as-propaganda (either by an oligarch or an unfriendly state), or as philanthropy (why not run ad-free 'worthy' television as a modern version of the Carnegie Library?)