That's only if you're using roaming on your home provider which I doubt many people are. Most people visiting China are either one WiFi (thus are inside the Chinese firewall) or are using a travel (e)sim which usually routes packets through one of the neighbouring countries/regions. Last time I was there Tailscale with my exit node terminating at a residential British IP address worked fine on both but discovering relay nodes on WiFi didn't work so I had to switch to data.

Which is also why you get Google results in your own language, even if you're in Japan. Google receive your requests from an IP address in your own country.