This the same reason why the FCC can regulate content on the airwaves, but can’t over cable. There’s no public property involved.

Hopefully, constellations of satellites providing Internet can take over almost entirely, so public property in the forms of bandwidth and orbits can justify such regulation. I say hopefully, because the current big tech culture has shown that it lacks the ethics to create level playing fields and curb its own biases.

Ideologically biased actors in YouTube are basically engaging in ideological manipulation of the market within its walled garden.

To what? Without a convincing basis for the government to regulate a type of speech (like a limiting resource that needs to be licensed), your new law isn't going to make it past the first supreme court challenge.

Space on the recommended section and monetization is a limiting resource. Basically, human attention and the sum total of all available information are valuable and limited resources, and manipulation of access to those has potentially dangerous and far reaching consequences.