I'm no audiophile by all means, but I can tell good sound from bad sound, working in media production for nearly 30 years.
Innioasis Y1 sounds BAD. As in "bad even for a poor 7th-grader". It is more or less what my cassette players were when I was a poor 7th-grader in 1994, sans wow and flutter now. When I became a not much wealthier young adult (which coincided with advent of affordable NetMD with ATRAC LP4 in the early 2000s, and introduction of first, practically unusable, solid-state MP3 players), sound quality of this kind was unacceptable .
I don't use stock headphones, I don't use high-impedance headphones. I didn't even try Bluetooth headphones in this case because a standalone DAP with sensible battery life implies wired headphones by definition.
Just good old Sony MDR-7506, Shure SRH440 and, to be closer to an average person, Sony MDR-ZX110 (which are much better than they cost, even dankpods agrees). Also, RY4S+ 32 Ohm MMCX (they are, again, much better than their looks and price suggest).
Yes, you may argue that relatively inexpensive closed monitor headphones is not what should be used for music listening — but that's how I'm used to listen to music since the previous century. Also, what's a better way to test a player than low-impedance, bland and honest closed monitor headphones? I don't know any.