Some songs I have a hard time writing about because I just don't have anything interesting to say. I have a hard time writing about "Youth" because there's nothing I can say about the song that's even close to as powerful as the song itself. Every comment about the lyrics or the guitar line post-chorus just melts into "...fuck, man, you've just got to listen to this for yourself."
Writing lyrics like these is a huge gamble, because it compares loneliness and heartbreak to internal bleeding and delivering a whole verse that goes: "Well I've lost it all, I'm just a silhouette / A lifeless face that you'll soon forget / My eyes are damp from the words you left / Ringing in my head, when you broke my chest," which is just beautiful writing about truly profound emotional pain. The thing about going all-in on irredeemable sadness like this is that the music has to either be on the level of the lyrics or get out of the way entirely, and "Youth" does both.
First of all, it's impressive how much noise these people get out of a three-piece band (though there's some piano and effects in the studio version), but they can also back off and remove layers to give the vocals more room to breathe before putting the whole puzzle together in the choruses. Incidentally, picking their spots with the percussion and lead guitar gives the sense of thrashing around desperately in between verses, as a particularly distraught person might, plus various swells and decrescendos throughout the song.
That said, fuck, man, you've just got to listen to this for yourself.