And those are just verified. There are thousands of games that require nothing to play, there’s just a minor thing preventing Valve from approving it. (For example, a link to a web page in the main menu disqualifies it)

It’s more about the scripts being given a passover of approval from the CCP. Want your movie in China? Usually, there’s some adaptation for the region, no big deal. However, I remember articles coming out about how the movie adaptation may not be accepted if the U.S. version doesn’t fit the standard, meaning the U.S. version would have changes made at the suggestion of the CCP.

Sorry for the NYT link, but it has some examples

You can back it up on Steam. You can download your entire library to a backup haddrive and run Steamless, effectively the exact same process as you just described for itch.io.