Gentoo for me is not about compiling things from source, or "performance", or tweaking your OS for days, which seems to be the comment perception from people.
Now that there is an officially supported binhost, you do not have to compile anything if you don't want to. You can use a desktop profile with zero customization and have a system that works "out of the box". You do have the options to customize and compile but it's not required.
Gentoo's benefits for me include the tooling around portage and the PMS (package manager spec). Gentoo's software packaging tooling is (IMO) superior to what exists in Debian and other conventional (not nix) distros. The most similar would be Arch's PKGBUILDs, which are also pretty nice.
Packaging software for Debian, trying to create a .deb package is a fairly arcane process and the documentation was difficult to find and digest when I attempted this. Gentoo has a wiki section called "ebuild writing guide" that describes everything in great detail.
There are also benefits like being able to select on a per-package-basis whether you want "stable" or "unstable" versions of software. Gentoo is a rolling release distro, but requires packages to meet a certain criteria before being marked as "stable". You are not forced to use "stable" packages if you want the most recent releases from upstream (basically what Arch does) but still have access to them if you'd like.
Gentoo's community is the most important feature for me though. Gentoo feels like a proper open source project. You don't have to be a Gentoo developer to contribute, and you can interact directly with Gentoo developers when you need guidance or have questions. Gentoo's community seems to have a lot less elitism compared to other distros also which is very important to me.