The only Chinese sites I know of that are blocked abroad are the ones that are distributing TV shows and other media without paying for the IP. I don't really think of those as the same thing, but if I were to put on my contrarian hat I suppose I would say there is no such thing as a priori illegitimate content which is universally accepted as ok to block. It is legitimate to block things which break the law, and the stuff which is blocked in either country breaks the laws of the respective regions.
Taking my hat off, I think this is a false equivalence. Every country, nay every civilization ever, has laws against stealing. Theft is universally acknowledged as an illegitimate activity.
Chinese streaming sites like Bilibili that block non-Chinese users from watching certain shows are probably paying for the IP, but only have a license for China, so they need to block everyone else.
You seem to be thinking about foreign governments blocking Chinese sites, but that's pretty insignificant compared to Chinese sites blocking foreign IPs from accessing them.
Taking my hat off, I think this is a false equivalence. Every country, nay every civilization ever, has laws against stealing. Theft is universally acknowledged as an illegitimate activity.