For everyone in this thread saying "but the platforms!", I don't disagree with you. Extensive censorship exists. But I don't believe that's the intended purpose of this tool and the metrics it collects. It doesn't measure censorship at what we would call layers 4-7 in the OSI model. It's concerned with IP reachability and layer 3. It collects valid data for that purpose.
Do they distinguish between "censored in transit" and "blocked by destination"?
In the last years many sites started to drop/block connections from the countries like China and Russia. It is sad to see how Internet is becoming more and more fragmented.
Many websites block UK IPs rather than comply with some recent KYC laws.
The latter one isn't censorship, it's geofencing. Which is incredibly unfortunate (and always has been), but it's not censorship.
Which is a type of censorship.