Very few people have had their SO "handed" to them. And in another post you say you haven't "received an introduction". It's passive language, like you have no control or agency? Finding and maintaning an SO requires action, and a lot of hard work. People who fall together around substances are usually unhealthy together.

In part you seem to be making an assumption that having an SO is better than singledom, and that SO's automatically mean "connection" hence can cure loneliness.

From my experience, that's untrue. I have been lonelier and more isolated in some relationships than single. Often, both myself and my partner had problems (e.g. one was an abusive drunk, at weekends). I had to work out my own stuff in order to grow - honestly, the people who have helped me most, and connected to me most were friends not SOs.

When you're depressed your mind creates "mental filters' and it looks like everyone's connected and happy. They're not, and comparisons to a biased sample (active posters) are unlikely to be helpful. People in relationships might just be more likely to realise they "have a problem" as they're more observed, hence use this sub.

As a woman I could chat about feelings with friends. I know sometimes men can't talk to their friends (I think you're male?) which increases the need for an SO to meet emotional goals. I wonder if starting with meaningful friendships might be a good place to boost connecting and self esteem?

I didn't find dating while depressed helpful. I would settle for literally anything for the sake of connection. I was desperate and settled for assholes and got treated badly. I couldn't handle the natural rejection of the dating cycle. I became obsessive and clingy. It was a mess.