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.