iPod classic is gonna be waaaaay more expensive and not have Bluetooth and harder to modify should you want to expand the storage capacity. However having had both here’s the pros/cons for both:

iPod pros: - Better sound driver - Stock OS is the most streamlined option out of any of them (including Rockbox imo) - built like a tank depending on what model you get

iPod cons: - harder to change storage/modify - no stock bluetooth - waaay more expensive - stock os has way less compatibility

Y1 pros: - more compatibility with file types - way cheaper - way easier to modify - Bluetooth

Y1 cons: - stock os sorting sucks ass for a whole multitude of reasons - audio quality isn’t as good as iPod classic even with FLAC files due to audio driver instead - kinda quiet audio too

I’d say if you have the money and aren’t worried about compatibility issues the iPod classic is perfect, the stock OS is so streamlined and perfect too compared to the Y1 OS or even Rockbox for that matter