I just discovered that my extension type handlebar plug was almost impossible to remove, at least without lasting damage/complete destruction. Until now I only ever encountered "push-in" plugs, which have a slightly bigger, but flexible part that holds the plug in place when pushed in. Currently the only difference I see is the former is potentially not removable, the latter is unproblematic in that respect. However there must be a reason for the existence of expandable plugs.
How do push-in plugs as handlebar end caps compare to expandable type ones, i.e. what are the respective advantages and disadvantages?