I find it exceedingly hard to make new friends as an adult. When I put effort into it, eventually I reach a critical mass of acquaintances through which I can find those few rare actual friendships, but it's an enormous undertaking. I move around a lot, every few years, and have to start fresh.

The old standby is hanging out at the local pub. Historically, it's been a good starting point, especially if there's a pool table, dart board, or trivia night to encourage more active socialization. Most people I meet this way are just "bar friends" or casual acquaintances, but eventually I meet some real friends and move past "drinking buddy."

A less-boozy (or at least less booze-focused) path that works for me is finding a nerdy board game group. That's about it for my meat-space hobbies, though; I'm not into sports, excersise, fishing, crafts, or many other social activities. At least not enough to build friendships in any reasonable amount of time. I'd go to a makerspace or something if there were any nearby, but I'm in the suburbs, bordering on rural.

With the pandemic, I'm not even trying. There's no way I'm getting together with a group of strangers indoors, and even outside I'm wary of being around many people.

It's easy to fall into the trap of building a moderately-satisfying online life. All my good friends are online, whether they started out as meatspace friends who are just geographically-distant now, or are people I met online. It satisfies the social itch to some degree, and there's no barrier, so it ends up being the most convenient outlet. If it weren't for online communities, I'm just barely social enough that I would find meatspace friends to satisfy my needs; as it stands, the convenience of online friends--while only partially satisfying--usually wins out.

I've never been one to actively seek friends. I enjoy having them, I miss them when we're separated, and I'm happy when I make new ones, but my friendships are always accidental. I don't think this is uncommon; it's just that it gets harder as I get older, because I'm not going to concerts, house parties, school, etc.

Most people my age have kids and families, and they connect that way. They become friends with their neighbors who have kids, with their kids' parents, with people they meet at kid-related social events, or they bond with strangers who live the same sort of life they do. I don't have kids and won't be having kids. I end up making friends with people 10-20 years younger than me. That's fine with me; in a lot of ways we have more things in common, and my sleep schedule and weekend schedule are far more compatible with theirs than with people my age. It's a bit socially awkward--or even frowned upon--most places I've been in the US, or at least in the suburbs. When I've lived in some places, particularly college towns, it's been easier. When I lived in Cayman, it's such a small place that all generations mingle, and parents mingle a lot with single people; it was easier to make friends there than anywhere I've been.

Again, none of this applies in the pandemic. I'm resigned to online socialization until it blows over, which I expect will be literally years from now.

I share your struggle and concern. There are a lot of lonely people our age out there (I'm 47).