I'm CPU-bound on one of the games I play, and cachy's scheduler may have made a difference for me. I was also fully on the closed-source NVIDIA drivers in Fedora, and had been totally out of the loop that that the kernel driver had been open sourced. And, cachy had me on a more recent version of the driver.

None of these things are truly unique to CachyOS, but nonetheless I do think I experienced a boost when I switched.

That's still using Cachy's kernel. Cachy uses a different scheduler and compiles for x86_64_v3 instruction set. It won't get you a world-shattering boost but ~5% is what comes up in benchmarks.