He seems to suggest that "small-scale social groups", "family ties" and "local communities" are both important and non-substitutable.
But I know of way too many people who were physically and mentally abused by their family for years, kicked out on the street by their family, or who were ostracised by their local community, often just for being who they are, if for any reason at all. Many end up committing suicide due to feeling hopeless being stuck in such situations. This is not because of technology (the opposite, usually), and in many cases technology wasprovides a vital lifeline for such people to find community online, to form bonds with people in other places, and to find a new local community that accepts them, and they go on to live happy and fulfilling lives.
Even within an accepting family, there could still be various mental conditions, personality conflicts or tendencies that could make it difficult for someone to connect with their family, that could make one feel entirely alone even among people who are trying their best to connect with you. Technology could similarly help here with getting people to connect with others (especially others who are more like them), or it could provide resources for families to understand one another better and connect through those barriers.
None of this necessarily takes anything away from people with strong family ties and who value their local community, but it does give another option for those who don't, or those who want or need to supplement that with things they can't find in their local community.
Technology can and do help some families and local communities be more connected.
It's easier than ever to instantly share information with dozens, hundreds, thousands or millions of people. Many people do use technology to keep up to date on local happenings, to organise local events and to form local groups based on similar interests.
It's also easier than ever to keep in touch with other individuals. Plenty of people communicate with their partner constantly throughout the day, practically every day, for example (plenty of other people don't, and that's fine too).
He might in part just be objecting to capitalism (but who knows whether he sees it that way).
People need to move to new places to financially survive in modern society, or they want to move there because they want financial security or because of the culture which deems how much money you have to be one of the primary ways to measure one's success in life. Or, on a more positive note, they move because that allows them to pursue their passion - if someone stays in their local community, that could severely limit the range of career paths available to them.
It's more that this is enabled by technology rather than this being necessitated by technology. The driving force there is not technology, but rather financial needs or desires (or natural human variation in terms of interests). Technology was built within a capitalistic society, so it supports capitalism. If you dislike capitalism, you should push back against capitalism, not technology.
(For what it's worth, I don't think capitalism is bad in principle, but I do think capitalism in its purest form leads to literal slavery... which is bad. And even if you aren't quite there, that doesn't mean it's good. Capitalism seems to be least harmful if supported by regulation and welfare, and there's an argument to be made that this combination also provides the greatest benefit to innovation and improvements to society.)
None of this is to say that technology is all good all the time (which I hope is already clear from my last point), and we definitely should be responsible and thoughtful in how we develop and use technology. But it certainly doesn't seem justified to say it's as bad as Kaczynski suggests, nor that it's more bad than good.