Absolutely not. I see a huge number of iPhone users for in person tech support and most use the Apple Mail app. These are ordinary people who know nothing about pocket computers.
Even many people familiar with pocket computers use the iOS Mail client. I was an email user over a decade before Gmail existed, and I used mutt for most of those years. I happily use the iOS email client because of the OS integration, clean UI, well-designed interactions, and decent support for wherever my email happens to live that year. I think mostly it’s because I’ve dicked around with computers enough in my life, and I’ve no interest in doing so with my phone, too.
Thanks for your data for sure. I used to work in customer facing hardware support, but only have my friends and coworkers to go off of now.