[Eomer of the Rohirrim]

I don't think the remark about the staffs of the five wizards indicates that they were used for magic; it seemed rather to be about personal glory, and treating the staffs themselves as trophies.

I cannot think of examples of the staffs being used as instruments of magic.

It's possible that the staffs of the wizards became symbolic -- but then, other men had staffs, and Gandalf at least got a new staff quite easily. They are for leaning on. The Istari need them because they have the bodies of old men.