Here in Switzerland, and in France, Spain and Tuscany, etc, there are 1000s of Brits who have lived here for yonks and barely speak a few words of the local language. On the expat Forums the main questions seem to be 'where can I find a plumber, a doctor, a vet, a solicitor, a carpenter, a hairdresser, etc, etc, etc, who speaks English?'.
My take on this as that it is very basic courtesy and respect to make the effort to learn basic communication in the language of a country you've chosen to live in. And of course it makes all the difference when it comes to good relationships with neighbours, tradesmen, local authorities, hospitals, and so on. I cannot fathom how anybody would go and live abroad and not make that effort. Many rich British expats here live in a bubble and a parallel society, which puts locals backs up and also mean that they pass by so many wonderful opportunities. Many ask on an expat Forum where they can find a job where they only speak English, for Degrees, MBAs and PHDs in English, etc.
At least many of the very poor immigrants who come from war torn zones and very poor areas of the world have an excuse - as many have not benefited from a good education. Many of the BAngladeshi parents where I used to teach couldn't read or right and spoke only Silhetti - which is a dialect of Bengali.