Folks buy new headphones for their phone all the time. Just get the right one. Headphones with wires fail all the time, so wireless is arguable better for most folks most of the time. The arguments about sound failures are cherry-picked to ignore that. Also phones are compromised by every hole in the case (water, dirt, static etc). So now there will be fewer catastrophic failures. And now you can walk with your phone…
And yet I've got three pair of $300 headphones in my house between my wife and I, two of which are 6+ years old. If you take care of high quality headphones they will last quite along time. Wire wears out? Replace it. Ear pads lost their shape? Replace them. So yaaaay dongles? Which that's even more fun because if I'm listening music for any length of time, there's a portable amp in between the phone and my headphone…
The only problem I have with your comment is this line. It sounds great in theory, but in practice I've found that getting replacement earpads for my Sennheisers is not that easy: new earpads are almost as expensive as the headphones themselves! Or I can get cheap Chinese ones, and they aren't even that cheap, and have simply terrible fit and thickness.
Seriously, I think there's a great market opportunity here for someone who wants to make OEM-quality high-end headphone earpads. The Chinese ones I've tried actually seem to have decent enough feel quality, it's the size and fit that are all wrong (they don't really fit the headphones, and the pads are too thin, and many don't have the mesh inside).