Why?
Obligatory reality check for what PC gamers are actually playing in the real world along with related
Best of 2024 page...
Concurrent player counts checked at any arbitrary time are almost always going to be completely filled with major esports/online titles with huge long term playerbases. Most of these titles are not graphically intensive and are easy to run on even lower end hardware. Counter-Strike 2 is in there as a pretty good modern representative of that class of game. Most of those major multiplayer experiences are extremely difficult to design and run a reproducible test for anyway.
Major AAA releases that acheive huge playercounts only tend to do so for a short period after launch as everybody jumps in to play - take Elden Ring, Wukong, STALKER 2, Cyberpunk 2077, etc from the Best of 2024 charts for example. Those are all still modern, popular single player titles that plenty of people are purchasing and playing, but by their nature aren't building up a continually returning player base over many years enough to regularly keep in the concurrent players charts. If you're buying anything over a 60-class GPU are you not doing so primarily to enjoy better performance in modern eye-candy heavy titles?
Techpowerup likes to test out the reference cards very little benefit with Nvidia AIB cards compared to AMD.
Using the reference designs provides the most accurate and reproducible representation of the products, and in particular most accurately reflects what
most buyers are actually getting. People like us having a discussion in the comment thread of a post about a GPU test setup update on an enthusiast tech website are in the extreme minority. Most people are going to figure out which tier of card they want to buy and are going to pick the cheapest option. They're buying the cheaper MSI Ventus over an Asus TUF or whatever else because they don't have the knowledge or experience to know what the difference is or why they'd want to pay more for the more premium card.
It's easy to take that consistent reference baseline and get a good general idea how much difference a given AIB card might have by comparing a dedicated review of that AIB card and adding on the performance delta.