My son and I just upgraded to Manjaro (from Ubuntu) this summer. I, for sure, experienced a performance boost in the game when I did it (laugh away, I was getting 20-40 fps on Ubuntu with this rig and now I bottom out in the 30's on 64 zombie horde nights but generally stay around 50-60 except near large POI's). Game is vanilla (although I do run my LAN server on a zobees-7daystodie container which means Docker's running, too) and everything else about my OS is vanilla (out-of-the-box install of Manjaro).
OS: Manjaro 21.1.4 Pahvo
Kernel: x86_64 Linux 5.10.68-1-MANJARO
CPU: AMD FX-8350 Eight-Core @ 8x 4GHz
GPU: Radeon RX 570 Series (POLARIS10, DRM 3.40.0, 5.10.68-1-MANJARO, LLVM 12.0.1)
RAM: 4906MiB / 15987MiB