1) 4" phone users who have no viable option, even in Android-land.
2) Price sensitive users who want something to get them in to the eco-system.
Apples problem is conflating the latter with the former, they see iPhone SE sales booming and consider that it must be because they need a good entry level low cost phone, then the iPhone 8 and iPhone XR comes out to lackluster sales[0][1].
So they re-release the iPhone SE and sales boom again[2].
Apple, I don't care what it costs, I do not want a phone that is not operable with one hand. I'm a guy (with relatively petite hands) but I can't imagine how it is for girls. The idea that I have to stop what I'm doing to interact with my phone (putting coffee down or whatever) is stupid.
Technology is a tool it does not need to engulf my life, it should be able to be as discrete as needed.
[0]: https://www.forbes.com/sites/bensin/2017/10/23/why-is-anyone...
[1]: https://www.forbes.com/sites/ewanspence/2019/01/09/apple-iph...