The 14900k is a better all round CPU, as the 7800x3d is a pure gaming CPU, that is favoring single core performance and cache, as that's what most games still utilize.The more I read, the more I think the 14900K is a better performer for the newest games that can use the additional cores. But as always, the GPU is likely the bottlneck here. Since I've been down pretty hard with shingles, I've not done anything on the computer front.
However, as you noted, that is slowly changing. More and more games start utilizing more threads and cores and I have a feeling the AMDs gaming x3d CPUs may start to fall behind in those.