Which one do you prefer and why.
If you’re in a noisy environment and want to block out the noise, this is a terrible option. I tried using it on an airplane and could hardly hear anything.
I mostly agree with your other two points, but not this one. You should never try to “cover” noise with louder noise; that is just a recipe for hearing loss. Instead, you should be wearing some form of ear protection. Earbuds are not designed to function as hearing protection, nor are most headphones.
With bone conduction, you can wear regular, rated earplugs to block out ambient noise without blocking your audio. I find that I can usually lower my audio volume significantly when wearing earplugs.
I meant general expected background noise where hearing protection may not otherwise be necessary, like an airport or airplane. In those cases, I use my $10 wired earbuds. The silicone alone blocks most noise because it’s not at a damaging level, and the sound from that doesn’t need to compete nearly as much as a totally open-ear solution like these bone conduction things.