Forums aren't gone. They just were never really big to begin with. Reddit eclipsed all of them to the point that most forums were irrelevant unless they were highly specific (not like, a gaming or show community) or couldn't be on reddit (straight piracy with linking, other stuff we won't talk about)
They're not even gone, just the communities that want them are fewer and far between.
One thing that happened since I joined the feddieverse is that I've spend more time on the underbelly of the internet. Like, the other day I found someones blog. Not their tumblr or anything, their own personal blog.
It looked like shit and was filled with pointless entries but it was the internet in it's rawest form
Yeah, specific forums for games or apps are still here, they're just pretty empty unless there's a big community for them. Some companies intentionally make forums their first and best place to get info, honestly.