Update: I did find a mistake, a clip got duplicated and appears twice. But it’s OK, I’m resisting the urge to reupload because so many of you have already put time & effort into leaving such sweet comments. 🥲
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app