Bluetooth is fine but like other wireless technologies its not about quality but convenience. Its more convenient not to have a cord handing down when I run so I like wireless. Its easier to get in and out of the car with music if I can wirelessly control and listen. Thing is, cable connected sounds better. Cable connected networking is generally better as well but less convenient.
I'm fine with Lightning headphones and don't mind if they only work with the phone. I have lots of "older" style headphones around to use with all of the other devices. Its not a big deal if the pair only works with the phone.
I actually find bluetooth LESS convenient. Just having to pair/unpair, which i know only takes a few seconds, is much less convenient than plugging/unplugging my headphones. For some reason my iphone, even after disconnecting from a bluetooth source, always tries to reconnect to that source if i'm still in range. Which is annoying. Especially when I'm playing games in the bathroom and there are other people in the living room and i didnt realize it was still playing through the bluetooth speakers in the living room.
And when driving, even in cars I bought this year and two years ago, when I'm connected via bluetooth, the display shows less information, I can't use all the features (like activating shuffle), and the volume is lower. For all those things to work, I have to be plugged in.