Anecdotal: I'm not a power-user, but I never really had bluetooth problems (latency, connectivity etc) between my phone and bluetooth devices.

I do however have the rare bluetooth connectivity problems with laptops, even the newer ones, but that could be a problem with Linux.

Also, I've accidentally damaged my wired headphones before by walking around and the wires getting hooked onto something.

Besides, I find it convenient to keep my phone in one place and walk around while making phone calls, or listening to stuff. Like, cleaning my house while listening to stuff.

I agree that it would be better to have both BT and a headphone jack.