I work with Apple products all day and work with people using them every day. I can’t remember when we had someone who actually plugged in their phone to do anything other than charge. My company has been working with iPhone users every day for years so we’re talking thousands of people. I have a pretty good sample size and would say that our work basically amounts to extensive research.
Also, just look at the responses here and otherwise. Even the number of people that still demand a headphone jack is limited to techies and less-than-single-digit percentages.