I'll say the same thing that I always do. For some reason, it's not popular, hereabouts, but it's worked for me, for over 45 years.

Get involved with volunteer/gratis work. Join an advocacy/charity group. Do stuff for free.

HN members have really valuable skills that can make an enormous difference.

Joining a volunteer organization brings together passionate, action-minded people that already share a common platform.

It can also teach us a lot. My personal career was significantly helped by what I learned, doing volunteer work.

Boom. Loneliness problem solved.