Yeah, also the file archives seem broken in places... and there are often no download links to files.

But this idea isn't about post numbers.. It's about simply being able to feel cool because XYZ!
and be among other people who are XYZ..

One thing that could be done to maybe encourage activity, though, is put Google ads on the site only for people who post fewer than 100 posts per month, so when they exceed that amount, the ads disappear until their 30 day moving average drops below that amount. Perhaps restrict access to certain sub-forums too

That's possible, but I think more likely it would encourage people to either make junk posts that contain no actual content or just use add blockers.

Well it would at least encourage people to contribute rather than just lurking for months without posting and hopefully reverse the downward spiral trend. At some point, if activity continues going down, Omnimaga (and other sites) will need to use even more desperate ways  in order to convince people from posting instead of quitting calc forums to spend their entire time playing Minecraft and other stuff like that. As they would say in French, La survie d'Omnimaga et de toute la communauté de programmation est en jeu.

That's what the TI community has become in this age of smartphones, powerful computers and Minecraft. It's only going to get worse (although it might improve if the 84+CSE gets popular and if Axe/Grammer comes out on it), so eventually we might even have to pay members to post. (and I think the staff will go through every possible way before considering re-enabling the spam forum in its current form).

As for spam, you can always lower the post count requirement a bit, but do like Cemetech and count words per posts (excluding Quote/Code) and in addition to that also count downratings if the post has less than +1 rating. If somehow someone posts good posts only and still get ads then he can always report it (the staff will figure out it's suspicious post rating activity)

Of course, though, those ideas would be if activity really gets bad, such as Spring 2007 or Year 2008 levels.

Try to be careful to not do anything without admin's permissions, though.