Geekbench doesn't compare stock rigs, it compares benchmark results - commonly used by overclockers, even those who go to extremes like liquid nitrogen. The benchmark results this is being compared to are also heavily overclocked and tuned systems.
For example : https://browser.geekbench.com/v4/cpu/13481225
Single-Core Score Multi-Core Score 6178 56017
Memory 65536 MB DDR4 SDRAM 2101MHz
Name Intel Core i9-9980XE
You can see all 9980XE Geekbench results here: https://browser.geekbench.com/v4/cpu/search?dir=asc&page=1&q...
This 3950X result is definitely not faster than the top overclocked 9980XE, but it is faster than something like 3/4 of them. Given the base clocks of each I would expect the stock 3950X will end up at least slightly faster than the stock 9980XE though.