Craigslist isn’t a tech company. It’s a website. Not trying to disrespect them as I’m sure they do some impressive stuff behind the scenes to handle scale, I just don't feel they’re innovating in a way to be called “tech”.
Also a large portion of craigslist here was just the personals section - once that was shut down there is basically no good reason to use it anymore, as it simply doesn't have the network effect / critical mass of users to sustain itself. The remaining users all seem to be work-related scams of some kind (probably automated) and drug dealers (probably cops).