A wide range of games that lacks any ARPG representation entirely, it lacks MMOs almost entirely, it lacks flight sims almost entirely, it lacks factory building sims almost entirely, it lacks MOBAs entirely, it lacks RTS almost entirely. It is not like they don't test online games because online shooters get tested but other other online games, nah too difficult.

That is bias, especially when many of the games tested are no longer popular or played much. This is why the 'CPU don't matter at 4K' nonsense narrative exists, because these are the titles commonly tested.

That is not to say the AAA titles should not get tested because of course they should but in a 12-15 game suite there is room for current popular AAA games to cover the most relevant engines and APIs along with staple showcase games like CP2077 as well as other genres and game engines. Just drop the no longer relevant AAA titles to make space for some of the genres mentioned, especially for the titles that have long legs. This is something the German sites do tend to do better. PCGH and ComputerBase both have broader review suites and include more sim heavy titles as well as the current popular AAA games, just want the English speaking sites / channels to catch up.

Also there is no guarantee X3D will do well in all of these titles. Take Stellaris, it is great early to mid game but if you are playing on a huge map by late game performance is still bad because the cache is not enough and you end up having a lot of stuff in memory. You see the same in a lot of factory building sims too, great to begin with when cache can do the heavy lifting but as it grows and grows and you rely on memory more and more it normalises back to the non X3D performance give or take a bit. BeamNG is not a great X3D showcase either. So this is not an attempt to make X3D look even better than it is, but just an attempt to increase the breadth of what is tested so you can compare across more use cases.

TLDR. Current gaming CPU reviews focus too much on AAA titles and don't cover the full breadth of gaming, it is like if a productivity review suite was just 10 different 3d renderers and ignored other productivity apps and then people drew broad conclusions about productivity performance in from a narrow test suite.