There is a really critical component of having an SSD, and knowing you'll have an SSD (as a game developer) which is easily missed (the article may cover this, but just to reiterate).
Lets say you only have 8gb of memory. Most importantly: You know you'll have 8gb (not more, not less). You build your game around having 8gb; textures are a specific size and quality, levels are designed around this, etc.
With a hard drive (or disk), games don't just store what is "on-screen" in memory; they have to store everything which could reasonably be expected to appear on-screen within the next, lets say, 10 seconds. This is because disks are slow; if the player violently flips the camera around, they can't wait 30 frames to page in the textures for that wall behind them; it has to be stored, even if the player isn't using it, and may never use it.
But, with SSDs, this changes entirely: new textures can be paged in within just a couple frames. Now, that paging can happen more on-demand.
So, wait: This means that 8gb of memory, which previously contained N% textures just used for what is being rendered, and M% textures which weren't being used, can now contain even more textures for what's just on-screen. Those textures can now be bigger! Higher detail. Bigger open worlds. The like.
Second point: Series X and PS5 do have ray tracing (not just ray casting, which you seem to suggest they don't have?) The Ratchet & Clank video we saw during the PS5 press conference seemed to showcase this, as it had multiple scenes showcasing reflections that didn't seem possible with just screen-space reflections. These consoles can absolutely, 100%, do super-1080p rendering at 60fps with ray tracing. Maybe not 4k60, we'll see, but 1440p60 w/ ray tracing is clearly attainable, at launch.
Third point, and this is critical, possibly the most critical: These consoles are all built with the same underlying technology that powered the previous generation; they just turned the dial to 12. This has, in the history of Playstation at least, never happened before. PS2 was very different from PS1. PS3 was a clusterfuck of technology that took developers years to get their heads around. But PS4 to PS5? Same platform tech. Developers know these platforms; the ramp up will be startlingly quick, and they'll be able to re-use and improve many of the very powerful game engines already there on PS4, like Decima, to make use of the new tech instead of starting closer to scratch like they did with PS4, PS3, and PS2.
I really don't think you could be more wrong than your assertion that this generation isn't going to be big. I'll go one-further: The media is underhyping the impact these technological advancements are going to have, and this generation will be the biggest single-generation leap in technical performance since the Nintendo 64. Only one AAA cutting edge title that I'm aware of was capable of consistently hitting 4K60 on a previous generation console (Gears 5 on X1X), and really, most games looked more like Control or Fallen Order (barely hitting 1080p30, no impressive technical achievements on consoles). We're now entering an era where practically every game will be 4K60, with substantially increased graphical fidelity, with ray tracing, with 3D audio, and it wasn't enabled with some crazy technology like IBM Cell; its the same shit that everyone already knows.