I have an admin, and people who treat her poorly pop up all of the time. She’s a trusted person who can wield whatever authority I have in many scenarios. Treating her poorly is rude and gross, but also self-destructive (hint: who actually manages the budget?). Plus, she won’t be an admin forever, and it’s a small world.
I worked in retail sales in college and encountered all sorts of people. You get a sense of people when you work with the public. When somebody chooses to exert power over someone where that person lacks agency to respond, that’s a character trait worthy of future consideration.