to achieve that, devs most likely had to or rather "would" have to spent more money/workhour than they'd actually earn off of from 8 GB GPU owners. at that point, devs will see how fruitless it is to do so. it is not about being able to do it or not, it is about profitability. exact same reason why many devs bitched / keep bitching about Series S and its limited memory buffer. it is always possible to optimize things, but the more tighter the budget, the more work it requires.
we're at a time where nvidia still releases brand new 8 gb gpus, and most likely NVIDIA funded them to fix textures for 8 GB cards (this is not a joke, as they themselves said in their VRAM defending post about how games received "patches". this means that they most likely motivated these studios to do actual, high impact fixes.. . but that won't last either. it may last for another 1.5 - 2 years (to keep 4060 4060ti 8 gb revelant for another 2 years of scamming end users)