1) Wired headphones perform better
This one’s a gimme: Bluetooth simply doesn’t have the bandwidth or the performance ceiling to keep up with the best wired headphones. That’s not to say that all wired headphones are better than all Bluetooth headphones. Oh no. That just means that the performance ceiling—and floor—is much, much higher. Ever wonder why the most high-end headphones out there are all wired monstrosities chained to amps? It’s because Bluetooth can’t hack higher quality audio as well as wired cans can.
This may change in the future with advances in battery design and Bluetooth technology. Heck, it may even change with the most recent update to Bluetooth 5. Still, in order to have a set of Bluetooth headphones that competes with, say, a Sennheiser HD800, you’d need a strong neck to support a monster battery, good shielding, and a very loose definition of “competing.” Though there are some really awesome Bluetooth headphones out there: those are the exception, not the rule.
Bluetooth does a really great job at transmitting “good enough” music for commuters, and that’s great—but when engine noise and other sounds mask out lots of notes in your music, it’s a pretty low bar to clear. Though most people can’t really tell the difference between a FLAC file and an MP3 file at 320kbps, the point here is that Bluetooth’s ceiling is merely at that point; the actual average performance is a bit lower. MP3 compression may be able to maximize quality by deleting out sound we can’t hear, but you can definitely tell when you lose quality after a certain point.
In the future, wireless audio will easily beat the crap out of our current wired headphones where audio quality is concerned via digital audio transmission. However, that day isn’t today: and if you really want the best of digital audio, you need a cable—be it USB-C, Lightning, XLR, or your standard 3.5mm.