Well, the 9950X3D is a few frames faster in most games. I think that the lowest I would go, in terms of cores, is probably 12-core for a desktop. However, I really like the Ryzen 7 9800X3D. But, I will probably get the 9950X3D, or either the Zen 6 Medusa CPU when it comes out.
Ryzen 9 9950X3D vs Ryzen 7 9800X3D - Test in 12 Games​
Ryzen 9 9950X3D vs Ryzen 7 9800X3D - Test in 12 Games​