The purpose of bone conducting earphones is that they don’t obstruct your ears, so you can still hear everything around you with virtually no distortion.
I’ve only ever tried a pair of Aftershokz (though I think they’re rebranded to just Shokz now), and they were pretty decent. I only listened to about 5 minutes worth of music, but the quality was pretty good, though it felt ever so slightly radio-y; not that I could hear static or anything, but just that there were some missing tones on the higher and lower ends, like I wasn’t getting the full spectrum of sound that I should’ve been getting. But it’s hard to tell if that’s because I’m just so used to traditional earphones that go for sound isolation or if that’s just expected fidelity loss through bone conduction, and I don’t have any other experiences to compare that to, unfortunately. This was also quite a few years ago, so the tech may have improved since then, too.
I liked 'em, I thought they were pretty neat. If I worked in an office where I regularly had people come up for my attention or needed to clearly hear everything around me, I’d probably get a pair just for that purpose. Though personally, I still prefer earphones that offer some sort of sound isolation. The “openness” that you feel with the bone conductive phones is pretty cool, but I wouldn’t want it for situations where I want to really focus on the music.