So, what he says about the top RDNA3 GPUs is true, there's about 2x the number of transistors (compared to RDNA2), but the raster GPU performance isn't anything like 2x as fast. I personally found RDNA gen 1 unimpressive, but it doesn't get a mention. At the time there was lots of talk of 'Big Navi' eventually arriving - But AMD basically admitted there were scaling issues with the first generation - It's remains a problem in 2023...
The same thing is true for Nvidia's top Ampere and 'Ampere Next' GPUs, more than a doubling of transistors doesn't give you anything like 2x the performance (GA102 - 28.3 billion transistors vs AD102 - 76.3 billion transistors), so he is starting off from a false premise - it just isn't that simple. I think he's being a bit histrionic, considering that prices are going to come down further for RDNA3 GPUs, probably from September onwards.
Also, Nvidia already had a significant advantage with the RTX 3090 and 3090 TI in performance when these cards released - the RX 7900 XT beats or matches both.
It's quite possible that Navi32 GPUs will look unimpressive, relative to Navi21 - But still a reasonable upgrade compared to Navi22 (cards like the RX 6700 XT).
AMD's main with their new GPUs problem is scaling, contrary to what lots of people have been banging on about (clock speed).
You can see this just by looking at the RDNA2 consoles that struggle to reach 30 FPS at 4K in some titles (The Series X GPU has 52 Compute Units). They don't have enough Compute Units, I think you'd need at least twice as many to deliver a steady 60 frames per second at reasonable level of image quality, and this should apply for ray tracing also. 120 CUs seems like it would be a good target for RDNA4.
So people need to look at the functional units of GPUs, not the transistor count - because the architecture is different and is designed to do more tasks, like compute, AI and ray tracing. I believe the RDNA3 CUs are fairly well optimised - the issue is that there just isn't enough of them - they need to make significant power improvements with RDNA4, to allow for much higher CU counts.
AMD is not going to release a GPU which requires a 800 or 1000 watt power supply, presumably because it just isn't worth it (people buy the high end cards they sell anyway) and it would almost certainly require an 'exotic' cooling solution. Undoubtedly, they'd be much more difficult to produce also, at least with the current RDNA3 5nm fabrication process.
A final point on ray tracing in 2023:
There's really just one card that does 'well' in ray tracing and it (still) costs >£1,500, and is recommended with a 850 watt power supply.
But you can see that a linearly scaled up RDNA3 (or more likely, RDNA4) GPU ought to be able to match this level, and do it at a cheaper price point - but until that happens, we're a long way from RT becoming a standardised feature in PC games (that game developers put time and effort into optimising).