Nothing compares to the Oom M3. Hand crafted in the Swiss Alps, by a one handed crayon eating imp. Buy yours now on the jungle site (use a credit card and then just flee the country, rinse and repeat). The mic sounds pretty good I guess. Little more interference than I hoped for, but it makes up for that with sheer convenience and joy.
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