Yeah, sure sounds like fun doing the entire bluetooth "oh, let me pair, wait it's not coming up in my list, maybe you need to unpair first..." etc. dance over and over instead of just swapping out a cable in a second.
Tangled cords, frayed and broken cables, finding room for those cables...yeah no thanks. And maybe you need better devices, never a problem on my iphones. Just pop in my airpods and just works. Or start my truck and it just works. Or switch on my bluetooth speaker and it just works. Seriously, bluetooth has evolved to the point that wires don't make sense to me anymore.
Many cars disable Bluetooth pairing while the car is in motion, so you couldn't even "be the DJ" if your phone was not already paired with your car/truck beforehand. It's fine if it's just you and you are pairing just your phone, but if your friends wanna participate on a road trip and just want to use their phone it could be a problem.
Having a headphone jack does not prevent you from using Bluetooth. Not having a headphone jack makes your phone objectively less useful.
You were presented with a usecase where a wire provides a convienence that Bluetooth can't match. How can you just ignore that and say wires don't make sense?