The audio wouldn’t be a drain. It’s the video that kills you. It’s especially galling when the video consists of a few still images in the video.
My consumer Cellular plan gives me 2GB of data. Plenty to check email, news headlines, and my weather app. YouTube could rip through my quota in a afternoon.
Is it possible to save bandwidth and listen to youtube audio?
TLDR, most of the online music industry has moved to streaming models (with downloads available). Spotify, Apple, Google, Pandora, it’s all similar. Doesn’t really matter much. You pay a monthly fee (or endure ads), listen to most available mass-market songs, and you can download albums or playlists to your phone.
I chose Google just cuz you get music and youtube both without ads.
Most of these places have family plans, too, if you can get a few friends & family together. Cheaper that way.