Yes you need it. I have a great pair of BT headphones, but I also have a great pair of wired headphones. There are times when I would prefer to use the wired ones, not the least of which is when walking through a busy city where BT likes to cut out from all the interference.

Our Mini-Van also doesn't have BT. I have to use my USB-C adapter which means I can't charge and listen at the same time. Very inconvenient on long trips when I'm also using the phone for navigation.