In any case - approaching this as if it is damage, will end up putting you in opposition to choices people are making.
You can be incredibly alone in a crowd of people. You can be empty when people are singing your praises.
Meaning - is different simple social interaction. People can find their comfort zone of personal interaction is much smaller than others.
TLDR: Treating it like a problem, results in bad suggestions. Treating it like a choice, suggests that one look at the options available to people.
It may turn out that people aren’t hanging out at bars, but at home. Frankly, why wouldn’t people stay at home, if home is where they have put their time and effort into setting up.
If you want a good place to find solutions, look to boredom and monotony.
Do note - polarization started well before the personal computer showed up in the geological record.