Yes, I recall the content of reddit being much better around the same time you describe. There was a vast amount of actual original content produced directly by the users there at the time, and the quality of discussion was very good.

Over time as more people joined it, it seemed to become more and more of a sort of parody of itself, sort of like when you make a friend and introduce them to your group of friends, and they begin to use an inside joke that existed before they were there. Sometimes it's still funny, but it is an odd feeling that when this new friend tells the joke, you can tell they don't exactly understand why it's funny themselves.

Reddit to me felt like this to the nth degree when I left. I suppose it really is a result of some kind of "herd" behavior; people just acting a specific way or saying specific things because they saw other people doing or saying the same things, but to the point it no longer goes any deeper than that and becomes bereft of any real meaning or deeper thought or variety.