Well theres a number of reasons for that. For starters, Im under the impression that a lot of people have left.
Its been running for so long, threads are repeating themselves.
The age of the users is a bit high - I reckon most active users to be between 20-35 if memory serves me, so theres no time to invest to something like an internet forum.
Like, honestly, I dont care what you people say or think, Pokemon Sword and Shield are crap.

I dont know if theres such a word as "overmoderation", but if theres is, in few sites have I found it more present than here. Its impossible to have a proper conversation criticizing or bashing something we legit dont like - cause its taken as an "unproductive conversation". I keep hearing all the "good" folk got permabanned long ago. At times, the thread itself might not be discussion-worthy, and still gets locked. Just a couple of days ago they erased the "unpopular opinions" thread for no reason whatsoever. There was no insults, discussions, or anything of the sort, just a bunch of dudes sharing a bunch of unpopular views, and yet they locked it. So unless im here to say "X" thing is awesome and I hope it does well", discussions are limited. Seriously tho, Pokemon Sword and Shield are crap.

Its not just the moderation tho, people in general get triggered very easily - and in general are very serious in this particular forum. I've said this before, but bar a few people I find the treatment people have with each other in here to be very stiff. Even in the offtopic threads.

Maybe you're misremembering that thread? There were absolutely insults, and people using it to troll pretty heavily and derail the thread, hence the decision being made to close it. 

Pants are boring. I'm declaring VGChartz a no-pants zone! NO PANTS ALLOWED!

Oh how I could pick this post apart and give answers and opinions galore... but honestly it's a little too much effort and I feel it'd be taking us offtopic, so I'll just stick to the OP lol;

I don't really find that the site has gotten boring... some areas have definitely gotten more quiet, whereas on the flipside some areas have gotten more lively. For example my Nation thread has had quite the increase in posting recently, thanks in part to the user I'm quoting here lol. The only answer I can really give is that activity levels fluctuate throughout the year and as news comes and goes, which can lead to more or less discussions... but for the most part I'm fine with how things are, and have been, since it hasn't affected the areas of the site I visit. 

Pants are boring and I'm tired of pretending they're not. 

Maybe you're misremembering that thread? There were absolutely insults, and people using it to troll pretty heavily and derail the thread, hence the decision being made to close it. 

Edit: Turns out I'm the one misremembering the thread, as I was thinking of a completely different one that WAS closed for the reasons I mentioned lol. The one you're speaking of was closed in part due to the OP wanting it :)

Wait, you mean they actually perfected the technology but we'll never see it?! Why must I live in the world I do?!

The issue with VGC is, at least how I see it, it's not wrong to say that a lot of the most interesting people are gone or have been banned. But a lot of those people were toxic. Yes, those people did make posts (I might actually be in the minority opinion that a certain frog was probably one of the least bad out of the bunch of very bad influencers despite being the most pervasive and long-lasting) that were funny, or interesting, or often not even either of those things, just somewhat "engaging". And, those people never got replaced by good users, nor even equally bad ones to take their place as the influx of new users is smaller. 

In general though, it's probably better for the site to die with mostly good people than to extend itself another year or two with flame wars. 

Pfft you just mad the guy didnt like a studio

Oh, I see what all this is about... ;)

Never played The Last Of Us 2 and never plan to do so. Also happen to think Naughty Dog is a group of rather overrated uninspired trend chasers who tend to make what everyone else is doing, just with shinier graphics... But, some people have taken it to the point where they act like Neil Druckman broke into their home and pissed on their toast. At a certain point you're gonna get bopped with the hammer.

Long ago.

I find the people left are a lot more just arguing about brand warfare and feel "flame wars" as you call it. Before I remember I could joke around a lot more and people got it was a joke. Now I can't even joke without someone getting mad about something.