Wow, look at me finally uploading. . . . So I haven't really watched much of this type of ASMR but I thought it'd be cool to try it out. There's nothing much to say so happy relaxing!
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