Maybe it is for you, but there are plenty of people who invested their time and energy to build this site from scratch, keep it running, write effortposts, post daily and weekly megathreads, moderate the forum, ban wreckers and so on. Just because you're not putting any effort into it doesn't mean that other people aren't.

As for its roots, there was a lot of shitposting on CTH but it also served other purposes. Its users radicalized plenty of libs. People shared experiences about canvassing for Bernie and going to protests. It had impact on the real world, no matter how modest.