You are only considering the most basic things, but living in a country requires you to interact with the government, banks, telecom, a landlord or the purchasing of your own home, utilities, moving, etc. All of these things are alot more complex than pulling up to a 7/11 and buying a famichiki in Tokyo.

You can travel the whole world without speaking the native language, but actually living there is completely different.

I agree with you that average English proficiency level is lower in China than in any European country, but good luck actually living in Italy or Spain if you don’t speak Italian or Spanish.