Certain hobbies facilitate meeting like-minded people.
I recently got into a social deduction game called Blood on the Clocktower in the last couple of years (linked a nicely-edited online playthrough video which I think was originally recorded during lockdown). It's like a face-to-face Among Us, similar to Werewolf for those who know it but friendlier and more inclusive. It's expensive to own, but requires a large number of people to play and there are local open groups all over the world who play it. I play once every two weeks in a pub in my local city and it's a great time. I've met loads of people I really enjoy being around. I'd consider many of them friends, and even if I only see them at the games I'm still socialising with them regularly.
Obviously not everyone is going to enjoy lying to a bunch of strangers (and being lied to) within the respectful context and rules of a game, but it's an example of something I started doing recently which has done wonders for my personal wellbeing. Doesn't cost me anything to play other than the drinks I buy at the bar. And some people just drink tap water all evening, so I guess it's free for them.
Another example: five(?) years ago a friend had recently broken up with her long-term partner and came to visit us. She was concerned that she didn't really do anything which helped her meet new people. I told her about the time I met a colleague of mine in a bar who was out with a social group which exists literally for the purpose of anyone who wants to meet people in a social environment.
It must take a bit of courage to go along to one of these for the first time, so again I know it's not for everyone, but she went along. We're all glad she did, because she's now happily married to someone she met with the social club she joined.
These are two specific scenarios that fit for me and my friend. There are many options out there that will fit other people better, but I guess you have to know where to look (and of course have the motivation to, which is arguably most of the problem when you're fighting depression).