To celebrate the unofficial end of what I refer to as "Troll Season," I thought I'd take a moment to read some of your awesome comments! Thank you so much for your kind words! I really enjoyed reading them! :)
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