I can identify somewhat as well, though I've had some friends in the past. Most of them disappeared eventually, so I guess I didn't have much to offer them.

At 29, you can still make friends in various ways, such as forums, games, chats, etc., based on shared interests. I've met people online and later followed up in person (at least pre-COVID). The main thing is to have something that connects you, such as those shared interests. If you're on the same wavelength, that's one way it can last.