Looking for advice for a new Gaming-CPU/GPU

I'm planning to upgrade my gaming PC and would appreciate some advice on choosing the most important components. My budget is around €2,000, but I'm willing to spend more if the extra cost provides a meaningful benefit, such as noticeably better performance, better longevity, or a more future-proof build. I mainly play Path of Exile 2, but I also enjoy shooters (like Marathon) as well as games like Elden Ring and World of Warcraft. I'm based in Germany, so stores like Microcenter aren't an option.

I've already decided to go with NVIDIA and I'm currently choosing between the RTX 5070 Ti and the RTX 5080. I know the RX 9070 XT is often recommended but I´ve read a few reports about inconsistent performance, driver issues, occasional freezes, or black screens. I'm aware that experiences vary, but I'd prefer to stick with NVIDIA.

I am mostly struggling to decide which CPU I want to use. I'm not sure at what point the CPU becomes a bottleneck for these GPUs, especially at 1080p / 165 Hz (I may upgrade to 4K in the future)

These are the CPUs I'm currently considering:

• Ryzen 5 9600X – ~€160
• Intel Core Ultra 5 245K – ~€200
• Ryzen 7 9700X – ~€230
• Intel Core Ultra 7 265K – ~€300
• Ryzen 7 9800X3D – ~€380

The 9800X3D still seems to be one of the best gaming CPUs available. On the other hand, I often read that the CPU usually isn't as important as the GPU for gaming. Since I'm not buying something like an RTX 4090 or RTX 5090, I'm wondering whether spending the extra money on the 9800X3D is actually worth it.

Which CPU and GPU combination would you recommend for my use case? Are there any combinations that work particularly well together, or any pairings that you would avoid?