Gentoo's benefits come from having software specifically compiled for your specific CPU, which can take advantage of its quirks. Technically that's achievable with other distros as well; it's just a lot more work when it isn't built into your package manager. You can also eke out additional performance by building a custom kernel and removing various features that are meant to protect against bugs or security concerns, and while Gentoo doesn't push custom kernels as hard as it did twenty years ago, the capability is still readily accessible.

So: Gentoo makes it easier to access methods than can in theory be used to speed up any distro. The gains are either quite modest (for custom compilation) or not necessarily that good a tradeoff (disabling Spectre mitigations and other protections in the kernel). 🤷

(Yes, I wrote a serious response to a joke post. Bite me.)

Please read what I said again, and don't confuse the situation. You're discussing performance differences of an overall system being benchmarked. I'm discussing gaming performance. No one distro will outperform another in any meaningful way. Don't start being pedantic and throwing around minor benchmark differences to be "that person".