This video has shots of the set up.
A big part of the problem seems to be that there is a curb cut on the left, allowing the left wheels to ride up the curb and hit the first bollard on the left (and in the UK, the left is the passenger side, so it’s harder to judge the distance perfectly). The curb on the right, on the other hand, is an island with a curved curb that will tend to guide the right wheels around it.
Note that there is a restricter on the opposite side of the street, too, but without a curb cut just before the bollards. I don’t know if it is as narrow, but it apparently doesn’t cause any crashes. Which makes it seem that having a curb cut right before the bollard is the issue.
Here is a different angle of the set up all the cars are running into, showing the curb cut before the bollard:
