I don't know what's been going around lately, but there sure has been a lot of complaining, and ironically, it's mostly about too much/many pictures being posted.
Many popular threads are years old... it's not reasonable or realistic to expect every single user who's wanting to post a pic in that thread to manually pore over every single post on every single page of the thread to be sure it hasn't already been posted before they post, is it? I mean, which is worse: a dupe (or similar) pic getting posted, or us all missing out on a good pic completely, due to an overabundance of caution (about possibly making a dupe post)?
If the very act of seeing a similar or dupe photo is so off-putting, then all I can suggest is that you just don't open popular/active threads where it's likely to happen once in a while. Or, to be completely safe from dupe posting, maybe turn off your computer and cancel your 'net account with your ISP... only that way can you be sure that dupe posts won't rear their ugly heads in your daily life.
We've been here for between 15 and 20 years now... certainly by far the longest-lived and best-attended online forum on the planet for our shared interests. I don't understand why some people regard the unavoidable side-effects of such longevity (dupe posts, differing opinions/interests between users, postiing pix of retired models, etc...) as being so annoying as to justify publicly complaining about them. This is a diverse community of individuals and other users will wind up posting stuff you're not wild about... that's unavoidable. If you find it so offensive, maybe you should think about why...
Obviously, this is my personal opinion, and this isn't the best place to discuss it, but
1) It's very easy to miss a great new picture because it's lost in a sea of extremely similar photos. I'd consider that to be way more likely to make me miss a good photo than anything else.
2) This isn't a function of the forum being old, it's a function of one or two users, largely salem, who bump 10-30 threads a day with very similar if not the same pictures as what already existed in the threads. It's much harder to tell if a picture has been posted already because they've posted so many similar ones and utterly dominate posts from any other users. Up until a couple of years ago this wasn't even remotely an issue, and as you mentioned the forum had over 10 years before that.
3) My understanding was that the entire reason the 1-1-1 rule was created was to prevent threads from being a complete image dump from a particular shoot, but in reality posters that are patient and consistent enough are doing it anyway. I don't believe the forum was ever intended to be a place to catalog every photo of every girl with a thread, and yet that's how some users are using it.
I don't think I'm being unreasonable, and I'm not rabidly screaming at anyone. I won't bring it up again.