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 You're paying a massive early adopter tax; when a PC that currently costs $2000 is obsolete, this monster PC will be almost obsolete.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.