It happened just last week when I was buying a car. The sales rep kept insisting that I install the car company's app while I was trying to just write a check, grab the keys, and drive off the lot. "You can use your Google or Facebook identity to make signup quicker!" Not only can I not actually install the app, I don't even have a Google or Facebook account. Eventually he relented and showed me "his wife's" car -- which happens to be the most expensive car on the lot -- on his own phone so I could see how the app worked. (His wife's car had an odometer reading of 6 miles per what I saw in the app running on his phone, but I'm sure she just hasn't had a chance to drive it yet anywhere except home from the dealership yet.)
For situations like that I usually have to tell them, "I don't have a phone with me that can do that." Then they get really confused, convinced that I have no idea what I'm talking about that that all I have to do is open the App Store and search for the app. The problem is my "App Store" is F-Droid. Why on earth I wouldn't be cool with just handing over my privacy to Google or Apple is completely lost to them, and most of the time I have neither the time nor desire to try to explain it to them. So I just end up coming across as some weirdo asshole by refusing to "just install the app."
We need more people using phones that respect their privacy and that don't have an umbilical cord to Google, Apple, Facebook, Twitter, etc.