I currently have an i12700k, paired with a 4090 and i've really got the upgrade itch. Is it worth upgrading to a 14th gen intel/7950X3D or should i just wait until the next gen of cpus are released?
Depends what you do - there is around 10% performance increase for 1440p gaming going to a 14700K and 13-14% 14900, slightly less at 4K. But the uplift for productivity tasks can be 30+%.
Personally wouldn't recommend the 7950X3D unless you want to buy into the AM5 platform or can get a good deal as it is quite a bit more expensive than the 14700K without being hugely different performance wise aside from some specific tasks.