[AlexAltea]

Yes, but those are legal measures affecting higher levels of the OSI model, not low-levels technical blocks as OP implied.

Technical measures such as "not letting CN/RU on the Internet", involve at least blocking their IP space at BGP level (null routing as in China's Great Firewall), or even reallocating their IP space.

The Internet might be more or less fragmented at a high-level due to bureaucracy (see GDPR and HTTP Error 451 Unavailable for legal reasons or DNS blacklists), but at least everyone can pretty much agree where a public IP address points to.

Breaking up the very foundation of the Internet... that could get really messy and complicated.