Gentoo developer Michał Górny has written a lengthy article explaining the philosophy and purpose of the Gentoo Linux distribution, in response to a thread on Mastodon:

Gentoo is a source-first distribution, which means the primary method of installing software is to build it from source. Of course, that doesn't mean manually building stuff, following some kind of how-to: finding all the dependencies, installing them manually, going through a series of magical incantations, and eventually ending up no better than if we were installing a binary package. The package manager takes care of all the necessary steps and more, making package installs easy; well, at least unless something fails. But I'm digressing...

[...] We try to build a friendly and welcoming community around Gentoo, and we truly want using Gentoo be an enjoyable experience. We want it to be a system that doesn't betray you.