I know it sounds weird but I've actually made some amazing friends on Craigslist. I have social anxiety pretty bad and have issues connecting with women specifically; I get really shy around them so I don't very often make connections with them at work or in other public settings. Then I started responding to Craigslist ads where women were like me and looking for a female friend. You do need to be cautious and safe (I always have them send a photo with a sign in it so I know they aren't fake, make sure to meet in a public place, etc) but I've actually met some amazing people that way. Would not recommend it for meeting men/dates, but an underrated resource for meeting platonic friends.