Trap bars are ideal for injured backs.
You can load the posterior chain much harder with the trap bar, and turn it around you got a shorter (or longer) range of motion again saving or rehabbing your back.
If you're healthy however, "saving you shins" is not a reason to use the trap bar.
The proper reason is to:
a) Back issues/Rehab
b) Work on weak spots ie: Posterior chain
c) As an accessory to conventional deadlift.
Or you could replace squats with it - again for injury sake or accessory. Never ever actually Replace a Squat with anything lol.
But yeah, don't use it because it saves shins
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents... some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new Dark Age."
-H.P. Lovecraft