This is only the case if you buy a phone from your carrier (that they’ve customized to disable hotspot without you paying extra) instead of from a phone manufacturer directly. Carriers doing that isn’t as common outside the US, but it’s not an inherently location-based thing. I’m in the US and (due to buying phones from the manufacturer) I can use mobile hotspot without paying any extra even though my carrier would normally require that.
This is only the case if you buy a phone from your carrier (that they’ve customized to disable hotspot without you paying extra) instead of from a phone manufacturer directly. Carriers doing that isn’t as common outside the US, but it’s not an inherently location-based thing. I’m in the US and (due to buying phones from the manufacturer) I can use mobile hotspot without paying any extra even though my carrier would normally require that.