RTX5090 vs RTX5080?

Good Day, I’ve waited for the new GPUs to release, looking for a high end setup.

I just upgraded my pc (except gpu), those are some specs: Intel Ultra 7 285K DDR5 96GB

Now I have a 5120x1440 px screen on which I am gaming, a lot of people say 4K requires 20+GB, now I know my setup is not 4K, but calculated on pixel, it’s coming close.

Now to the question, the 5090 is 1000€ more expensive when coming out, but will the 5080 be making any sense considering the screen size? I also of course am looking for playing with good graphics, I don’t want to play on low settings when spending that money.

Thanks in advance!