This is an opinionated post and on purpose.
Everything on my PC is compiled from source, including kernel, kernel-modules, applications.
Trying the same thing on linux, i tried gentoo, it did not work, there was always a conflict. Meaning here I put option X there I must put option Y and you never get it right. So in some sense freebsd is doing something right what gentoo is doing wrong. But what is it ?
I build all of my operating system and applications from source on both FreeBSD and on Gentoo Linux. As Alain noted, there are far more failures trying to build software on Gentoo. It can be quite frustrating. I think I know why...
We have better unity of vision here in FreeBSD and appropriate humility/cooperation. In FreeBSD there is one version of each package in ports at a time. The FreeBSD project's build servers build all of those packages continuously with default (the commonly needed) options. If a package fails to build the maintainer gets a notice and typically fixes it within a day or two. The typical FreeBSD user wants a stable server or desktop system that is pretty-much just like the systems of the other FreeBSD users. There's not a lot of "ego" involved in choosing how to assemble a system. Assembling the system is treated as an engineering job. I love using the quarterly ports branch for increased stability. The support being given to Quarterly Ports is excellent with important fixes being merged from head as needed. It is good engineering.
In Gentoo there are multiple, sometime numerous, versions of
each package in portage at a time. There are many versions of the linux kernel and each user configures his kernel differently. There is no Gentoo build server to provide continuous integration testing because no two users can agree on a supported version of the kernel and of each package and a common set of default options. The users agree only that "Gentoo is all about choice!" If a package fails to build for a user the user can file a bug report but since no two Gentoo systems are identical the bug may not be reproduced by others and may not get resolved for a long time. The typical Gentoo user wants his unique system and, in my observation, is finding a lot of ego-satisfaction in finding his own choices to be superior and other's to be bloated or to include components that the user dislikes and judges, some hate gtk3, some hate Qt, some hate systemd, etc. When I build my Gentoo system from sources I do so for the "unstable" amd64 architecture and with an incredibly wise set of USE flags to avoid bloat and attain perfect usability. I like my Gentoo system. I like my stripped-down KDE Plasma there. And I refuse to run systemd the million-line abomination. When I build Gentoo my ego gets out and I'm tempted to be judgemental. It's a miracle that Gentoo works at all and it is a lot of fun.
I treat my time playing with Gentoo as a hobby. I play around with the choices and smile at the outcome. Then I boot into FreeBSD with KDE Plasma and enjoy
using my computer.
It's the egotistical attitude that afflicts Linux generally. Linux, some say, is all about individual choice. FreeBSD is more about group decision and teamwork.