Recently mobile phone operators introduced a “fair use policy”, so it’s not really a”roam like at home” anymore, but data volumes can be limited to a fraction of what you are entitled to in your home country.

This is a point where WiFi might get more important again when traveling.

If I had this in the US, I'd be cancelling my cellular service entirely, I'd still keep my home service though, to VPN into it for a bit more security when using a public wifi connection.

I would also just transfer my phone number to one of those cheap voip providers, then just use voip from my phone everywhere.