I've been here since 2015 and I still view the site regularly but I can also say that my posting has also dropped a bit, at least compared to what it used to be. There's just not much interesting on this site currently, especially after the sales charts went away, but in that case I fully understand why that happened and how it's better for the site ultimately.
As others have mentioned though:
1) Attempting to use this site on mobile is literally pointless as it's a nightmare that has still not been fixed. The site shows up as unsafe on desktop/mobile and the amount of ads make it unusable, at one point I was honestly worried that it might have put a malware/adware on my phone because one of the ads got selected by mistake because of how messy the site is so I don't ever bother trying to view it there anymore.
2) For as much improvements there have been made to the site the past few months, there are still some things that make no sense for what should be a modern website. A while back I was trying to look up what were considered "classic" threads on this site for a good laugh and wanted to find the "Are you a virgin" thread since I remembered that one and you would think a simple google search or website search would find it but nope, it's like it doesn't even exist anymore no matter what I typed. Why is even trying to find something as simple as a single thread here still so complicated/impossible?
3) I think overall the mod team does a good job and doesn't really restrict conversation, outside of super extreme situations, but there have been times in the past where I remembered seeing people get banned/warned/moderated for such simple posts that I ended up thinking "Wow, they got banned just for that?" to myself. It happened so often that at one point I remember making a post thinking I would probably be banned for it despite not even saying anything really bad in said post, just because someone or a mod might take it that way. I'm not sure how often this happens now, or if it's even an issue anymore, but I do think that probably contributed to some leaving as well over the years.
4) I do think the sales charts, which should have been the differentiating feature that brought people into the site, ultimately might have hurt it more in the long run. A lot of the time they were incorrect, to the point where it got the reputation of being super inaccurate and not to be used seriously, etc. Even for people who used this site it became that same thing of not even using them because who knows if they are correct or not, which is why I say while it sucks since they were fun to look at, I think it's ultimately better for the site that it goes with actual shipping data instead.
Ever since 2015 this is really the only site I use for talking about video games outside of reddit, so hopefully things can get better, and the amount of site improvements over the past few months are definitely a good start. With next-gen around the corner hopefully that can be a fresher start. :P
