Are you just itching to argue with someone for the sake of it?
@IntentionalPun isn't the arduous xbox defender spinning things the way you seem to think he is.
Firstly, there's two kinds of pop-in here, the loading one which I would classify as a bug I suppose, the other is merely a side effect of having LOD in games.
The first "on load" pop-in where the game logic finishes loading but not all the textures and geometry has I would call a bug. Not that it's faulty code mind you, but that from the end users perspective it looks like unintended behavior.
As mentioned this could be cleared up by just letting the game finish loading (filling RAM) all the texture data before handing control to the player. Sure this goes against the promise of no loading screens but I would argue it's the lesser of two evils. Either way I don't think it was MS that promised no loading screens but Sony.
Now if there is pop-in during actual gameplay it could be due to any number of reasons, but to say you can't blame the games, tools, developers or the universe (LOL) is ridiculous. If you're referring to a higher resolution asset popping in as you reach a certain distance from an object then all the speed in the world won't change this. Luckily UE5 will.
If it's not LOD related and assets are just failing to load entirely even when you're up close then it could be a bug or very poor asset streaming optimization by the developer, but to claim that as a whole "Series X has pop-in and texture streaming issues" is disingenuous.
We've had games running on hardware going back many generations now with a fraction of the bandwidth these consoles have, it's up to the developers to smartly utilize said hardware to make sure the right textures and assets are streaming in when they need to be and at the quality they need to be.
There is a third option which you may be implying, that the game was coded first with the PS5 SSD speeds in mind and not optimized at all for Series X. So when the Series X is told to wait until x distance or time before you see an asset to request the textures, but in reality it actually takes twice as long for the texture to load on Series X then you get this pop-in.
Alright I've rambled on long enough, back to work I go.