>>216732 (OP)It's insane how many people are on this website and genuinely do not understand how imageboards work. The community replacement of this site by tumblr/twitter/deviantart users is 100% real.
If you make a thread and it does not have enough activity versus the other threads, it will automatically "fall off" the board as other threads receive activity and still others are made. As threads reach their limit in terms of numbers of posts and images, they'll automatically start a process known as auto-sage, where further replies will not bump the thread and the thread will eventually be pruned by the imageboard software.
There's no "server space" being taken up by excess threads, only whatever threads are active and/or archived on the site. Imageboard threads aren't permanent galleries, they will eventually vanish if not archived. Slower imageboards can have threads that last for days, weeks, even years depending on site traffic.
Do not treat this site as an archive. Nothing hosted here is meant to be permanent. If you like something, save it locally.