Loneliness is a symptom of the loss of the third place. You can't solve loneliness, but we can as a society look at why many have lost their place for socializing.

Hyperfocus on productivity, the one dimensional man that know only rest and work, and the rise of narcisism and hyper individuality, all causes of the loss of the third place.

Everyone needs to take on the quest to find where they belong, but society needs to give people time to invest in this quest.

So I think it's as simple as working less and spending more time with people.