This proves that AC Oddysey runs faster on Linux than on Windows with your specific hardware. What this doesn't mean is that "Linux gaming is faster and smoother than Windows gaming".
Counter examples are Overwatch, CS:2, GTA V and many more.
Nobody reasonable doubts that Linux can perform as good or better than Windows, but claiming that this is true for all games is simply misinformation.
Wrong general claims like these lead to posts asking why their specific games run worse on Linux since they switched because they want more fps.
Don't get me started on older GPU's like 1000 series Nvidia that have problems with any vkd3d games so the performance is abysmal.
Why is it not enough that almost all games work on Linux with ±15% performance difference?