I think vendor prefixes are hurting the Web. They are hurting Web authors. They are hurting users of browsers. They are hurting competition in the Web browser space.
I’m tempted to raise my fist in disagreement, but you know what, I’m not an oracle. I can’t know the future nor know how the world would have turned out if we never used vendor prefixes.
Here’s a guess though: if we were to go back in time and influence the decision such that browsers agreed to never use vendor prefixes, we would be worse off. Less browser innovation, less of the spec implemented, and more serious cross-browser problems when some browsers jump the gun and implement specs prematurely.
Vendor prefixes, while being an eyesore and requiring maintenance, have saved us from a dystopian present (maybe).