The law in the US is that you can't make radio transmissions on TV / AM / FM frequencies without a license, because left unchecked, everyone doing what they want would make radio useless for everyone. The government has a clear reason to require licenses, and they have the power to restrict who can receive one.
The Internet doesn't work like that, though. No license is required to make a website or mobile app, because websites and mobile apps don't interfere with each other. The government wouldn't have a very strong argument to require websites to have a license, because they have no reason for doing that other than in moderating the content of the website, which is prohibited by the Constitution.
In the past, TV licenses were absolutely used to censor viewpoints the government didn't like, but now that is no longer possible, because nobody cares about TV or radio. You can bring in whatever content you want from anywhere in the world, thanks to the Internet. That is what the government is salty about; they are losing control because people don't care about TV anymore.
(I'll also point out that shortwave radio still exists. You can tune your radio to, say, 5910kHz and listen to CCP propaganda all day, and there is nothing the US government can do about it. On the flip side, we have Voice of America for a reason. We like broadcasting American propaganda into China just as much as China likes the reverse. Unfortunately, nobody listens to shortwave radio anymore. That's what the US is mad about; people like TikTok, but they don't have anything like it.)