Of course they are, I didn't suggest otherwise.
I do think families are more mobile and fragmented than they used to be. People are far more mobile, especially in large towns and cities, which is where most of the population now live. Family breakdown, the current system of shorthold tenancies, the bedroom tax, sale of what were council houses and with local authorities now moving homeless families to other towns 10s of miles from their home borough, those most in need do not get the chance to build up those close supportive networks based, not just on family but neighbours in a very small area were they lived for long periods.
My mother's family, Irish immigrants, lived in a small area of Bermondsey, for three generations and almost 100 years. My grandmother, a clever and socially mobile lady then succeeded in moving herself and her children to a semi-detached house in a pleasant suburb. The family are now spread all over the country from York to Lyme Regis.
If you are on a reasonable income, have access to computers, cars or can afford public transport then family and friendship ties can easily be maintained over long distances, but if you are poor, dependent on others as to where you live, the whole social welfare system set up to support you can completely fracture the fragile informal support system that also helps to sustain you.