I have been both a scribe and an MA, and I feel completey the opposite. I liked the fast pace insanity of the ER for the years I did it, but my job as an MA is infinitely more hands-on than scribing, where I was basically a fly on the wall. I room and interview pts, meaning I am learning how to take and present a good history (hello clerkships!). I am also learning hands-on skills like the aforementioned vitals and other things, including numbing pts for surgery and drawing blood. I also fill out the entire EMR, including coding, because we are present for the entire pt/dr interaction. I also help with PA's for medications, so I have learned a lot about what goes on behind the scenes (and how obnoxious dealing with insurance is).
What you get to do will obviously depend a lot on where you work, but, if I personally had to choose which experience has been more valuable to my ms future, it would be my MA experience, hand down.