I think its important to separate PC gaming and CUTTING EDGE PC gaming.
The problem,is he is right though to a degree when it comes to enthusiasts like us who have above average rigs, and the PC being a CUTTING EDGE platform. PC gaming for the masses is still fine,but as a CUTTING EDGE platform,I think sadly it is starting to wane.
The PC is about pushing the boundaries of what can be done in gaming due to generally having more processing power available to it and the quicker rate of improvements in the past over consoles,ie,Crysis was important not only for its graphics but its interactable environment,etc. Its a tech demo game,but PC has always needed them even going back to games like the original Unreal or games like Half Life 2,etc. Unreal was the Crysis of its era,and it really pushed PCs. Half Life 2 did things like awesome facial animations.
Games like Red Faction had environments which could be destroyed.
These pushed what could be done on a TECHNICAL level more than consoles could do. I have been PC gaming for over 20 years or so,and the slowdown has been noticable and I love PC gaming.
People forget that actually consoles used to be MORE cutting edge at times than PCs,before the rise of 3D accelerator cards for PC,ie,the first proper graphics cards. Look at games like Alien vs Predator on the Atari consoles when compared to PC games of the era. However,once PCs had their own dedicated cards they started to push past consoles 9/10.
However,Crysis came with the legendary card which was the 8800GT which was under £200 and close in performance to a £500 one.
The issue is that due to companies like Intel,Nvidia and AMD milking stuff more and more,the PC is not seeing as many of those jumps especially at more common price points,and it means basically there is less and less "need" to be buying top notch hardware since older computers or consoles are good enough as devs in reality might as well not bother.
Sure if you spend £800 on a card you might see nice improvements,but the figures show this is more a niche,a very profitable one,but still hardly mass market.
I give you a prime example of the slowdown.
So in 2014 we had sub £300 R9 290 and GTX970 doubling the performance of the sub £300 HD7870 and sub £300 GTX570 launched 4 years earlier.
Now fast forward to between 3.5 to 4 years later.
Something like an RX480/GTX1060 is barely 20% to 25% faster.
The GTX970 was in the top 3 surveyed Steam cards a year after launch. Last time I checked the GTX970 is still ahead of the GTX1070,and the later is at number 11. The GTX1060 is in the top 10.
The number of 1080p displays has increased massively displacing lower resolution ones. So that means,any performance improvements have been used by the higher resolution displays the average gamer owns.
So,if you a dev,why would you be bothered to push massively taxing graphical effects?? Its not worth it. Sure AMD and Nvidia might give devs some money to put in their effects,but most games won't bother.
I mean its sad when an XBox One X has probably a faster GPU in reality than anyone in the top 10 of Steam now.
The problem is if that happens,the increasingly PC like consoles look more viable,and what happens when the next generation have a Ryzen CPU core or something similar from Intel?? They only need to support keyboard and mouse better,and then a company like Blizzard does not need much to get something like WoW working on a console.
Yes,you might get a poorly optimised game,or one where AMD or Nvidia push some tech to sell more cards,but 9/10 most of those additions rarely are ground breaking.
If anything I have been following some of the bigger tech innovations,and they seem to be less PC orientated and more orientated towards consoles. Have you noticed how modern open world games seem to be able to do large outdoor areas without loading screens and with decentish detail?? Skyrim was one of the first games to be able to be able to do that successful as Bethesda had to get over the RAM limitations of the consoles,so you can see even back then even PC centric franchises were going more console orientated.
Its also increasingly worrying,that when you look at big gaming devs,that more and more revenue is coming from consoles,even in a number of cases,it being more than PC.
Its why you are seeing bloody microtransactions and "games as a service" model infecting more and more PC games,as these things came from mobile gaming and consoles.