Gaming on Linux is an obscure niche. A niche that is growing rapidly thanks to its use in handhelds like the Steam Deck. However, there is still a long way to go before it can compete with Windows. Unlike the latter, AMD graphics drivers are much more mature in Linux than their rivals. As the benchmarks below show (courtesy of Phoronix), Team Red is an obvious choice:
The Radeon RX 7600 is significantly faster than the GeForce RTX 4060, while the RX 6700 XT easily beats the RTX 3070 Ti. Further up, the Radeon RX 6800 crushes the RTX 3080, as does the RX 7700 XT. Oddly enough, the RX 6800 XT is faster than the RX 7800 XT. And this is the case in all games.
This could easily be chalked up to a CPU bottleneck, but looking at the RX 6800 something to do with drivers or API. Here the RX 6800 is almost as fast as the RX 7800 XT, so it could be a CPU limitation, but you never know.
Shadow of the Tomb Raider is a title that scales exceptionally well to fast-paced hardware. Once again, the RX 6800 XT decisively beats the RX 7800 This is also the only title where the RTX 3070 outperforms the RX 6700 XT.
As you can see, most GPUs move around from game to game, but the RX 6800 XT sits firmly in front of the RX 7800 F1 2022 produces the same behavior. The 6800 XT is in the lead, followed by the 7800 XT and the RTX 3080.
RDNA 3 GPUs don't seem to have much advantage in Linux. Besides the RX 7800 XT, the RX 7700 XT also loses to the RX 6800 in almost all games. In the example above, the performance gap reaches 26 FPS. This is not something you see in every scenario where the CPU is limited.