It makes zero sense. You're paying a massive early adopter tax; when a PC that currently costs $2000 is obsolete, this monster PC will be almost obsolete. It's dumping thousands and thousands of dollars for no particular actual benefit. If you're just seeking to fritter away your money, well, you're an adult and that's your prerogative, but let's not pretend there's any real-world benefit. It's a bit like paying $100,000 to get a 2021 Honda Civic two months before anyone else can.
As for 8K, it's unrealistic and a 3000 series card isn't going to bail you out there either; we're talking four times the pixels of 4K. You'd need multi-GPU solutions to get good 8K FPS right now (and almost certainly a year from now too), but games largely get either limited benefit from multi-GPU solutions or none at all.
Essentially, you want to pay a lot of money to have 2025 happen in 2020. That's just not an option.
This, pretty much sums the whole thing up. It's not realistic. It's not even possible really. You'd be a hell of a lot happier with the end result if you simply targeted very good 4k gaming, which itself is incredibly HARD to do, and do well, itself.
Plus, you'd need two giant 8k TVs to make it worth doing because there are no computer monitors that are 8k and large enough to even be able to BENEFIT from them BEING 8k, and if you are going to game on TV's (Which generally suck compared to actual monitors) you are going to have to put them so far away to even make them worth using that you're not actually, again, going to see any benefit from them because two giant 8k televisions far enough away to reasonably be usable isn't going to look any better than a much smaller 4k monitor would at a fraction of the distance.
Anything beyond 43" 4k is just ridiculous and doesn't actually serve a purpose or offer any benefit worth throwing money at. Even at 43" you'd need them to be at least five feet away from you or they're just a waste.
Nvidia 3000 series should be able to push 4k well enough to finally make 4k worth even considering, it will be YEARS before there is anything that can push 8k well enough to make it worth considering, and even then like I said, it's probably going to be a hard sell to anybody with any common sense. Unfortunately, there are a lot of people out there with more money than brains, so it won't just go away, despite the fact that it probably really should.