>>4142319People care less and less about interaction the more effortless and superfluous internet communication gets. That's what you're sensing here. There are still enough oldfags lurking, but they only come out when they recognize old familiar ones or when something really extraordinary is posted.
I have no idea how old you are or how long you've been here. Humans are in an abundance of images, are in a daily rush, many in responsibilities with jobs and family. One would maybe swipe pictures towards good or bad, incidentally on the subway, sitting on the toilet, that's it.
Back then, year 2008ff, not only was the internet still new at that time, but fresh for knowledge and sharing, uprising communities, but photography was accessible for the first time through digital ILCs and affordable both technically and engaging in. Recall, this was only the beginning of Facebook, then Youtube. Youtube went mainstream only after 2012 to 2014ish and was crap back then still.
So yes, /p/ and 4chan in general, was a lot more active then. Today, it's just a repetition of endlessly similar content. Unimaginative and uninteresting.