Buy a 5080 when they are released and then see how your 5950 does.
Buildapc
High resolution will tend to hit the GPU and not the CPU. If your existing CPU is working fine for you, I'd probably leave it as-is.
I'm not sure what you mean by "challenged." A drop from 60fps to 55fps? No fps loss, but high GPU temps?
You might want to look at the 5800X3D before worrying about an entirely different mobo, ram, and processor. If you're not doing 3D rendering or other multi-threaded intensive work, it might be the better option over your 5950X, and you could save yourself some money.
But if money is no object (and I wonder if you'd be posting here if it wasn't), then upgrading to any of the X3D chips would probably be a fine upgrade for many years.
Look at your bottlenecks for your applications, are you CPU bound? If not then don't upgrade the CPU
In case anyone is wondering how, MangoHud is great for monitoring system performance while gaming on Linux.
No, basically.
If your current CPU provides insufficient features or performance, then you should upgrade. Does it?