I don't wish to reiterate the points in favor of bumpers in regards to robot interaction, robustness and safety. I could argue for a while on those points, complete with nerf and metal baseball bat analogies

. My views on the how bumpers could have prevented the tip on Einstein last year are in
this post and at the end I call for mandatory bumpers. Instead, I will bring up how they reduce field damage.
The bumpers are soft and not likely to pop a trackball. Contact with a metal robot chassis at the speeds of this game is much more likely. To make matters worse your metal chassis is likely to be sharp. Why is it sharp? Because it is damaged from all the robot collisions that would be absorbed by the bumpers (if you had them). This is very noticeable when reinspecting robots for elims, the sides without bumpers always need filing. Popping a trackball is a
major disruption to game play since there are only 2 per side (unlike tubes last year where popping was minor, expected and there were more tubes). We now have a famous popped trackball from the SVR finals but I haven't heard of many other incidents (partially thanks to mandatory bumpers).
I would like to see the mandatory bumper rule back next year regardless of the game. I don't think they restrict robot design much at all in this game since the track balls are giant. I could see them changing the required percentage to allow for different mechanisms in future games. I would also like to see a standard bumper covering with a lower friction coefficient than the current cloth (so it can slip out of pins easier).