It's not really niche. The GP's problem is solved because pairing effectively becomes "put these two things close together and open the box".
If they were a pain, I would stop using them, but they are much less hassle than the many pairs of corded headphones I have. This said, other Bluetooth headphones are much more hassle.
That's an extremely narrow use-case. If that was the only thing people used the headphone jack it wouldn't have been the big travesty that it currently is (and will be for the foreseeable time).