It's not equivalent. Namely that's a CPU. It also is slower than its Ryzen equivalents for anything except professional work so it is undesirable and AMD will never be able to convince people that's a good deal even if they priced it lower.
GB202 will be faster at everything. It will be easy to convince pay pigs to buy it. Look how good of a deal it is compared to GB203. Amazing! But if there was a reasonably sized intermediate between GB202 and 203 many would choose that instead. Nvidia makes sure to not have an option which is a new and more anti-consumer choice.
There is no reason except profiteering and lack of competition for the 370mm² gap between GB203 and GB202.
It is actually worse. AMD can give you more cores at minimal cost. By reusing the same I/O die and using tiny chiplets, AMD saves on R and D and manufacturing which allows them to add cores for cheaper.
The 7950x is very cheap to make.
By using a monolithic design and having to design and do a different layout for each chip, it takes more R and D effort to manufacture GPU's. Combine that with worse yields from doing a monolithic design as a result of defects and edge loss, and it explains why AMD tried to do chiplets in GPU and why it is doing only 2 chips this generation with monolith.
AMD chiplet design allows them to scale cheap in comparison and save on R and D.
Also lots of people would want more core products, it is just prohibitively expensive to buy it from AMD with threadripper. One of the reasons why products also don't scale is because the parts are so low volume as a result of the price, software makers don't code for so many threads.
If 32 cores were more mainstream, we would likely see scaling with software at this point.