If a 2 year old chip is actually able to outperform AMD Renoir on SW emulation in games then x86 is truly screwed regardless what the geekbench results say and how many cores AMD decides to stuff into their next threadripper.
There's a bit to unpack here, so a few points:
The Apple Axx core may be good, but unless they acquired a magic bean to boost its power it won't do jack against a Zen2 64C Threadripper at heavy threaded compute tasks.
Threadrippers are not gaming chips - unless by gaming you mean gaming while the PC is doing something (or several somethings) in the background.
Threadrippers are basically workstation chips strangely marketed to gamers (they even have ECC memory capability, albeit unvalidated).
You are not directly comparing Apples to Apples here, if you excuse the pun.
There is no Renoir based Mac - so you are not making a direct comparison from Renoir to Axx on the same software platform, it's not even the same gfx code as the Mac version was written in Metal instead of D3D12.
Another thing to bare in mind is that plenty of games (SOTR included) can vary significantly in performance depending on the level being played as shown by the more in depth benchmarks over at Phoronix. This means that a short demo of a a single level does not in anyway represent the full performance of any system.
The Rosetta demo video was not an exhaustive benchmark but a demonstration, so you'll forgive me for being somewhat skeptical about the results?
Lastly I watched the Rosetta video - SOTR is a very nice looking game, but at that crippled low texture res it's hardly worth playing at all on any platform, so while certainly an impressive feat of binary translation it's somewhat unimpressive beyond that.