It also varies greatly based on content. With most 4 part pop bands with lots of dynamic compression in the mix, you'll barely need 192-256bit MP3. If you are listening to an orchestral piece and lots of voices, you sure as hell need something more than 320bit MP3 ( or equivalent). This is why I archive/'master copy' all my audio in FLAC where possible. I can always transcode them if need them smaller or in a specific codec/format for a replay device.
Aso for replaying, most USB DACs are trash. If you looking for good-quality playback, you need to have some good hardware, like a good USB DAC with amplification, a good set of noise-canceling over-the-ear headphones to minimize ambient noise. None of these things are convenient or very mobile. So yea, I completely understand why good audio isn't a big thing. Not many people have the time nor money to just for dedicated music listing. The best bet is at your work desk, but you are also concentrating on work, not the music.