So I have AMD Ryzen 7900 (12c/24t), it is amazing at blazing thru shader cache compilation.

I also have older Intel i7 8700 which is 6c/12t and OMG, it takes as much as 20-40 mins for first time shader cache compilation. I checked, yes all CPU threads are ~100 during shader compilation.

I am looking to replace the i7 8700 with Ryzen CPU, and this machine is primarily for gaming attached to TV.

Question: Should I get more cores eg: Ryzen 7900 or go for the best CPU for gaming 7800X3D ?

Yes, 7800X3D will give me the best FPS among the two. But honestly the shader compilation seems to be taking the majority of game launch time, sometimes I just want to fire up something for 10-15mins to chill, the shader compilation time tends to just go longer. Yes, I realize that this is a one time cost, but I noticed each time proton updates or GPU driver/kernel updates, it tends to run again - which is fairly often it seems.