one on hand Backpage removed one element of danger by having sex workers advertise online instead of being out on the strip.
However....whether people like it or not......prositution is illegal (Vegas has that gray area but still). Prostitution does go hand in hand with sex trafficking (not all of those women on Backpage are from here). Backpage was also a part of the problem.
Like someone else said, sex work can and should be legalized. But in order to do that, the elephant in the room has to be fully addressed--sex trafficking. Measures have to be taken to ensure that these women are in safe environments engaging in their activities safely. Backpage would never have vetted those ads to make sure they weren't aiding in the exploitation of sex trafficking victims because their policy was basically to turn a blind eye.