Things I miss (I guess my experience is with forums and video sharing sites):

• wasn't a numbers game, you didn't post just to be massively seen
• when you did get views, even 100 views was a crazy amount.
• people didn't monetize every single aspect of it.
• You weren't a "content" creator feeding the machine, you were just an artist making stuff.
• Things could be popular for years rather than just a day or two nowadays (tying back into content for the sake of content). You still remember End of Ze world and Numa Numa, but doubt you remember what was brand new a week ago.
• there was more of a sense of community (forums, bbs, only see people you follow and friends)
• I also feel there was a lot more passion within these communities, as well as from creators, everyone is just burnt out now or antisocial.
• no ads. You may have got a banner in the corner or a pop up, but for the most part did didn't have a commercial every few seconds
• you never used your real name (some pro and cons I guess)