Hardware

Well you don't really need any high-end CPU as a necessity, such products are essentially luxury goods.

One area where you truly do benefit from strong CPUs (and the X3D) are indie/AA "tycoon" and "economic strategy" games. Although they are never mentioned in reviews or really talked about in the mainstream press.

A seemingly simple game like Final Earth 2 will bring a relatively modern high-end CPU to its knees if you have a large map (much much larger than what you see in the screenshots) and disable the in-built population limit. Same with Project Highrise, if you enable the hidden setting for custom tower sizes (in-game limit is ~120 floors, you can "mod" it to have a tower with say 200 floors; but this has a disastrous impact on performance due to CPU bottlenecks).

My personal DIY single-thread "benchmark" is via a game called Cities in Motion (the first game from the Cities: Skyline developers). It's a single threaded engine. If you use modded maps that cover the max size supported by the engine (such maps were not included in the base game) and install the freelook mod, you get 5-7 FPS on a 5800X at 1440P with even with medium-level distance coverage (full distance coverage brings FPS down to 1-3) even in the early to mid game. I wouldn't be surprised if the 9800X3D would still struggle to support full distance coverage free look in the mid to late game.

Basically any complex economic strategy game with lots of units requiring pathfinding and draw calls is still very much limited by CPUs (even modern ones).

Pretty niche use case, but it does exist.