Mike-OI don't really get this argument that smartphones themselves have destroyed forums, there are masses of forums that are alive and well to this day that I'm sure are frequented mostly in front of a bigger screen. Maybe this hits NS the hardest because some of the more active posters have "come of age" and moved on and the new bunch isn't all about that tl:dr shit. It's an action sport, and if most can get their daily kicks off of Instagram videos and pictures etc. then they might not see the reason to dwelve deeper.
Nah man, this is a huge problem across the internet. FB/Insta/snapchat have taken over because they're apps. Our traffic is 50%+ mobile at all times, 5 years ago it was like 5%. I frequent dvxuser (camera forum) and it has had a huge decline in the past 5 years too.
The internet has just changed so much, Newschoolers used to be the only "social media" as we're a ton of other forum sites as well, then smartphones and fb/insta turned that all upside down. When NS was the only place to see skiing (well one of the few) the forums were huge, video views were huge, etc.
Now our traffic is only stimulated from instagram and facebook and google searches. We have a solid amount of people who still check the site like they used to, but its all older (18-30) while the younger generation doesn't even type addresses into a browser. We're hoping with a big launch of the app this fall we can bring in a ton of those younger users and stimulate the site overall with those people who never go to the site.