If training Traps i would do other exercises but my point is the Lats are not fully trained properly with Deadlifts, the upper back sure to a point & i think you´re correct in your points..but again i am not anti- Deads.
By the way i got my Trap Bar 
I absolutely get your point, JP does too.
If you like full range of motion, for traps I have one exercise I have never seen anyone else do IRL. Of course everything has been done by others but I came up with it myself back in the 90s. Stand sideways towards a smith machine bar and do one arm shrugs (straps absolutely needed). I almost guarantee you will feel the range is much longer compared to other shrug variations. A couple of fellas trying this claimed they saw some new trap growth after just a couple of sessions LOL. Donny, and anyone else, please try this just once and tell me what you thought

You can do this with a low pulley attachment as well.
Edit. Deads with a band for even more glute emphasis
