I have several pocket protectors, most of which have been well used (by me, personally).
Years ago I worked in an architectural firm and I needed to have at least half a dozen pens and pencils of varying colors, widths, etc, in my pocket at all times.
In that situation, a plastic pocket protector is the best and only realistic way to keep the tools of your trade handy and organized.
Today, I still keep my vital drawing instruments in these containers, inside my black bag.
Piss off, twerps!