I don't see this so much as there being, or indeed needing to be a purpose for a community. Members of many communities have learned new skills. Members of communities from the Indian sub-continent are to be found throughout the retain and IT industries, for example and also finance and law. Members of communities from Africa and the Caribbean seem very prevalent in the caring professions. Without people from non-English communities our hospitals would collapse, and there seem to be many many Eastern European dentists. These are not purposes as such, merely callings or ways to make a living.

The Traveller and Romany communities traditionally had a hostility to literacy and schooling (for Star Trek fans, consider the Ferengi), and as a result they are now at a disadvantage in the conventional jobs markets. But since the advent of mobile communication and the internet this need not be so, and for many many years there have been Travellers and Romanies (by descent) who have been conventionally economically active. I know tolerably well one woman who was born underneath a set of railway arches, and married a "muddy" (longshore bait-digger). Her children are for example in the police and teaching. She is largely retired but was a schools assistant. I know quite well one chap whose family were "carny" but he made his way both in logistics and in IT. I know very well another whose maternal ascendants were Romany, who spent a long time in the navy (becoming an officer) then logistics, eventually becoming disabled by back injuries.

It seems to me that there are two questions. Should the old ways be remembered and cherished? I think so. Africans and Caribbeans would be emotionally poorer if Black history were not celebrated, and First Americans and Australians should celebrate their histories. So should Travellers and Romanies. Secondly, should they be preserved without evolution? I cannot see that. In all four cases unless Disnified they would be pathways to being trapped in poverty and disadvantage. What would make sense would be modern educational access in a mobile context, and the enablement of sufficient access to empower an itinerant lifestyle until the carrot of economic empowerment caused that lifestyle to fade away.

It won't happen with conservatives racists and bigots in power though.