Every idea like “let’s have icecream socials at..” started as one person’s pipe dream which they then acted on and executed. No one is coming to rescue us. There’s no secret hand guiding humankind.
You definitely can’t solve loneliness for society but you can solve loneliness for your immediate circle by organising activities and that’s already a huge improvement.
In contrast, sitting back and saying this needs to be solved at a higher level does nothing at all.