>>74421218A source volume increase can cause more than just a volume difference in the output, depending what it goes through on its way to the air/ear. App to bluetooth to earbuds is just louder, which most people do prefer, but through an ojisan stereo (or any analog stage) YTMusic might really sound *better*—or worse, depending on a bunch of dorky crap.
Based on one listen, the normalization is too much for this song, lowering a bunch of subtleties out of the range of hearing, causing a general "shrinkage."