The barriers randomize each game session. They generally don’t set you off down a long alternate path though, as you may be envisioning. Rather, each barrier tends to only be a minor divergence but there can be several in an area so that they collectively mix things up quite a bit. Often it is still possible to loop around and explore the full area. The purpose of these is not to totally change the gameplay experience but just to get people doing things a little differently each time.
The person above who described themselves as always running along the same level wall out of habit is exactly what we hope to alleviate. That is the type of thing I might do and I think many others do just out of habit or for the sake of efficiency.
As an example, before we had the barriers, I had created various possible routes through the starting area but in playing, I realized that I almost always go the same way without really thinking about it. The barriers prompt me to deviate off the normal path now and it keeps things fresh.