Gentoo's source based approach was always destined to be less popular than a precompiled distro. Compile times & customization options select for a certain clientele.
I think the reference was to Gentoo's wiki, which was indeed hacked and lost data iirc.
But yes, comparing distros themselves, Gentoo will not out compete streamlined and prepackaged distros in the broader adoption metrics.
The wikis themselves are largely distro agnostic and exceptionally useful for everyone on Linux though.
All my machines still run Gentoo (I have used it for over 25 years). I just love the package manager. It has become much more low friction with the binary packages and gentoo-kernel(-bin). I regularly visit both the Gentoo and Arch documentation. They even cross reference each other and both are a great resource.