How do you make them see that the alternative - community, is better than material isolation?

I think they'd need to see how community is elsewhere- outside the west- to understand. Because there are so many reasons why material isolation would be absolutely preferable over settler-colonial community to most people regardless of ideology.

Community, and society at large, can be an empowering thing, something that betters peoples' lives. It can be a force for harmony and equality rather than racism, alienation, and all sorts of societal divisions. It can be a source of belonging, fulfillment, heritage and culture, etc. This is too often not the case, particularly in the settler-colonial neoliberal societies of the west.

Everything you said is valid, but within this society (and most) home ownership is stability. Rural home and land ownership in settler-colonial countries (or worse, landlordism) is another matter entirely, but home ownership is a metric that many communist and formerly communist countries, China included, are testaments to the importance of. And by "community"- well, there is community, but one has to seek out their own decent spaces here. The mainstream society here in Canada frankly, increasingly disgusts, horrifies, and terrifies me, especially as someone who is a racial minority and a communist. In such a environment, seeking to isolate oneself makes complete sense, though the preferable thing would of course be leaving altogether.