Well, yeah... if I had a 7000X3D, such uplift may sure not sound enticing enough for an upgrade.
But coming from a 7600X, it is a nice added bonus on top. Based on CPU benchmarks here, 7600X with 4090 at 1080p, it is 131 FPS (average, geomean). With 7800X3D, it is 185 FPS. And with 9800X3D at worst perhaps 200 FPS. So, around or more than +50%. At 1440p the uplift is even more apparently(?) - with benchmark saying 128 with 7600X and 191 with 7800X3D... But then at 4K, there is barely any difference between the CPUs(?), according to another site...
Anyhow, not pre-purchasing. Still sounds like a boost to me though. Respectively, still sounds like a nice CPU to avoid or lower a CPU-bottleneck with a next-gen GPU.