True, not all hardcore gamer are PC only, but most of them are on PC. Because best graphic can only be achieved on powerful PC that is irrefutable fact.  And not all hardcore gamers build  1500 USD , instead they buy GPU that cost 500 USD on par with 600 USD Xbox X and just upgrade their normal  PC instead building a new one. I don't see any reason to not upgrading your PC, but a loyal Xbox fans will probably buy Xbox X instead PC or go with Xbox and  PC 

30% will not be noticeable especially when most of xbox games are made using directX api that is good at scaling on many platform (consoles, many variant of PC on the market, future hardware compatibility)  but bad at optimizing on single devices. It's the opposite with Playstation API with their GNM and GNMX which is bad for porting games, bad at future hardware compatibility but good on optimizing one single device. 

Also there are more factors then just Teraflop number. like memory bandwidth, GPU speed etc etc. Even some expert said many game developer choose small CU count but higher clock instead bigger CU count but less cloaked frequency. PS5 are rumored to have 2 Ghz with small CU that will benefit on pixel rates and geometry shaders. On top of that  both are using the same memory bandwidth speed (Flute benchmark indicate PS5 will be using 18 Gbs of GDDR6 instead on the numer on the OP) . While Xbox will be using 56 CU with 1700 Mhz speed to achieve 12 teraflop with memory at 18 Gbs as well. This means it will be even far smaller then 30% in reality. This is very different scenario then PS4 and Xbox One comparison,  where the hardware is even bottleneck on  memory bandwidth. 

I think only very small people that can only tell the difference and you is one of them , also lets be honest here without going to Digital foundry nobody able to pint point the difference , especially when Digital foundry  pause the games, zoom in and out and bring the pic close together to compare it. Nobody really care that much. Probably only hundred thousand people like you who will care to see Digital Foundry to see the difference and  buy Xbox X many will just buy new GPU. And all of the person who go to Digital foundry are niche gamer and super hardcore.

Let's look on this gen on how a powerful Xbox One X is, It still unable to  changed their sales number. Content, price, brand is the most important thing,  power also important but on certain degree. 

@bolded: that's absolutely not true, especially when you have ray tracing lowering the fps count so significantly. at similar graphic settings can be the equivalent of playing at 30+ fps vs 60 fps locked

Both console will be aiming the same performance by tweaking the visual effect. we have seen a lot example with PS4 and Xbox One where Xbox has lower resolution or lower graphic effect ten PS4. We might see PS5 1900p while Xbox X run at native 4K. 

Me might see frame rates difference , but not as big with PS4/Xbox One different  . Also both will be using Variable refresh rate on HDMI 2.1 , so 10 to 20 frame rates difference will be hard to notice using Variable refresh rates.

Both consoles will be underperformed when using Ray tracing , so we will see a hybrid and more efficient technique  combination of Screen Space and texture based ray tracing.  

Not all hardcore gamers are PC only. There are plenty of hardcore console gamers who want the best visuals just as much as the next PC gamer in fact I know more PC gamers who play on PCs weaker than a Pro and an X and also there is plenty of info about the average PC gamer that does not have a high end PC. Not everyone wants a PC and that's coming from a PC gamer myself. I have plenty of friends who refuse to go out and build a $1500aus PC just to play games better than a $600aus console. 

As I mentioned before, games will always push the bar every new gen and they will eventually utilise 100% of the hardware in the next machines so having a 30% advantage will be noticeable. A better argument would be would console gamers care that much? Yes and no. Many console gamers this gen made a huge fuss over 900p to 1080p. You might not care but there will be others that do.

I don't need to zoom in to see the differences in games from a Pro to an X or an X to a Ultra PC game. I can tell, weather it affects my gameplay experience it doesn't. Next gen is going to be about what you deem affordable as its going a direction of how much you want to spend for quality.

with a much bigger power difference than the one between ps4/xb1, how can you say it won't be as big as then? if anything it will be much, much bigger.

and variable refresh rate only matters if your display is able to support it, i'm pretty sure my tv isn't, same for 99% of the people out there. you are making a lot of assumptions without anything to really back them up. history tells that graphics get pushed ahead of frame rate the majority of times, the idea would be to have powerful enough hardware not to have to compromise either vs the competitor.

#1
4,2 vs 6 Tflops = 30% differnce.
9,2 vs 13 Tflops = 28% differnce.

Its the same in terms of power.


#2
However with diminishing returns, and consoles at 6Tflops almost being able to run most things at 4k anyways, I think the differnces will be minor.
It matters more at lower resolutions. You can easily spot the differnce between a 720p image, and a 1080p.  Its alot harder with 1440p/1800p vs 4k (2160). Power matters less and less, in terms of sharpness, with increase of resolutions. You wont have 1 be blurry, while the other is sharp, the differnces wont be that big.

#3
"variable refresh rate only matters if your display is able to support it, i'm pretty sure my tv isn't, same for 99% of the people out there."
True... this will be the "next" big thing to get as a console gamer, a TV that has variablel refresh rates. So you avoid screen tearing, and have less noticeable lag, while playing.