CachyOS does compile packages with the x86-64-v3, x86-64-v4 and Zen4 instruction set and LTO to provide a higher performance. Core packages also get PGO or BOLT optimization.
CachyOS utilizes the BORE Scheduler for better interactivity, and offers a variety of scheduler options including EEVDF, sched-ext, ECHO, and RT. All kernels are compiled with optimized x86-64-v3, x86-64-v4, Zen4 instructions and LTO to be optimized for your CPU.
I like the sound of that for my new gaming distro, but I really feel more comfortable in the .deb ecosystem.
While this is broadly true,
-O3doesn’t have as many downsides as it used to, so some distributions are considering to move to it (like Ubuntu).It was a mess in the early days, though, with not just performance issues but outright crashing being a common problem.