So I am in California now. Before I left Taiwan I paid for Chunghwa’s roaming package.
Once in California I notice I can not surf websites like Home Depot which is geoblocked.
When I checked my IP I am still in Taiwan.
But if I used my friend’s WiFi I am indeed in California.
I would suggest an app called Airalo if you have a phone that supports ESIM.
Cheaper than roaming and actually also easier . Just buy the esim before departing on a flight and you have internet when you land. Used it so far in Europe, Singapore, Thailand and Malaysia at least. If trip is very long then get a local SIM card.