I think that the things are connected and the primary reason for the PC gaming decline lies in the too wide spread piracy and devs being not happy with their profits. Hence, they stopped making such games like FarCry, Crysis, Need for Speed, DiRT, Quake, Counter-Strike, StarCarft, Diablo, F.E.A.R., S.T.A.L.K.E.R, etc. Games with which we used to benchmark our systems and always looked for more powerful components to upgrade in order to run the games.
They make some but those look like low-budget low-quality products (maybe with some exceptions):
True,its easier to make wall gardened systems more of a cash cow,and companies like EA are trying to do the same for PC now. However,these companies also must have an inkling of what cards are coming.
Think about it. Crysis was released and a 8800GTX was not cheap. But within the same rough time period all of a sudden we had 8800GTX level performance in significantly cheaper 8800GT and 8800GTS 512MB cards and ATI basically had 2900XT performance in £100 to £150 cards. Good timing,right??
Crytek must have known this - imagine if they had released Crysis before the 8800GTX was released(it was essentially mostly a DX9 game with some tacked on DX10 features),it would have probably not sold even the number it did originally.
Then look at Half Life 2 - we had fantastic cards like the 9500 and 9700 PRO. A lot of these taxing games,tended to come when at least ATI or Nvidia had released a really decent value card. At least that is how I remember it!
If they know the market is stagnating unless AMD or Nvidia pay these companies to push features,it makes more sense for companies to not really try and push games technically.
Look at the Final Fantasy demo benchmark - it looks like they tacked on all the Gameworks features at the last minute so it ended up being an unoptimised mess.
Sure,we have poorly optimised Early Access games,but then you buy those with the view they are incomplete and will have crap performance,but its cheaper than the finished product.
However,in the end it is what it is,so what to do??
I will simply just upgrade less if the performance jumps I need to materialise don't happen,and I need to spend more at each upgrade cycle.
Edit!!
I still hold out hope the GTX2060 will be a decent upgrade over a GTX1060,as Metro:Exodus is out this year. New uarch,12NM,etc.