The only part that I think is outright in error is the idea that one is less likely to be GPU limited with a higher-end GPU. It's true that most people buying RTX 4090s aren't playing at 1080p, but an RTX 4090 is much more likely to be CPU limited at 1440p or 4k than a mainstream GPU is at lower resolutions. The 7800X3D is definitely faster than the 5800X3D, or anything short of a 13900K, in some fairly common gaming scenarios, just not the ones tested here, and not where one is maxing out the eye candy to fully load an RTX 4090 at all times.
Elite: Dangerous Odyssey is a good example of a CPU/platform limited title. In high CZs I'm CPU/memory limited as often as not with my very well tuned 5800X3D + DDR4-3800 CL15 + RTX 4090 setup at 5k well-past-ultra settings. A 7800X3D + DDR5-6200 CL30 setup with a similarly clocked RTX 4090 can finally make those scenarios almost completely GPU limited (still have a more detailed comparison on my to do list). Same goes for plenty of less well optimized less-than-AAA titles.
The rest of the points are contextual. I ordered a 7800X3D for my brother's system on launch day, and the platform price differential was essentially non-existent. If anything, with equivalent hardware, the AM5 setup was cheaper, except for the CPU itself. This guy in the video is using a budget AM4 board and budget DDR4, which isn't a bad idea for a 5800X3D, but he's also using comparatively higher-end hardware for the AM5 setup. CL30 DDR5-6000 using Hynix M or A-die on AM5 (which can be had for $120 currently) is the equivalent of fairly well binned Samsung B-die on AM4...and a good B-die kit is still $150+. You can just as easily cheap out on memory for AM5 and the 7800X3D will tolerate that fairly well, not that I'd recommend it for an otherwise high-end system.
What's neglected is the potential upgrade path...there is none for a 5800X3D system. That is the fastest gaming processor that is ever likely to exist for AM4. AM5 will support at least another full generation of CPUs, possibly more.
He does have a point about ITX motherboards, which one of the reasons why I hesitate to recommend using them for AM5. They are overpriced and under featured, or have poor layouts. The AM4 selection is much more mature. However, if you move up to mATX--and if you're putting an air cooled RTX 4090 in your system, you don't need to increase total case volume that much to accommodate an mATX board--the prices and feature sets are much more reasonable. If one isn't going to overclock, there are competent $125 AM5 mATX boards and even if one is going to overclock (via curve optimizer, which does help even the 7800X3D) then one is looking at a $160 entry point. Personally, at the time I built the system I've mentioned, the best all-round option was a $180 Gigabyte B650M Aorus Elite AX.
Some of the complaints on cost also seem bizarre in relation to other component choices (though these were probably sponsored). That SIlverstone PSU, for example, is total overkill. An entire 7800X3D system, sans GPU will only consume ~100w, maybe 150w if you deliberately push it. The default power limit for an RTX 4090 is 450w, and it's efficiency sweet spot is down around 350w. I would personally be entirely comfortable running a 7800X3D + RTX 4090 on a quality 650w PSU, though would probably recommend more for upgrade and overclocking headroom.
Overall, it's more of a critique of the sorry state of AM5 on mITX than anything else. That the cheapest of these boards are $280+ is pretty inexcusable.
Anyway, for almost any brand new build, I'd recommend AM5 over AM4 at this point. DDR4 is not less expensive than DDR5 any more. Boards are also not terribly different in price, except for mITX, and even then I'm not sure the savings is worth tying one's self to the old platform.
