Because there actually are some desirable features only on iPhones. iMessage is the big one, but also many app developers--and college students around me!!!--treat Android users as 2nd class citizens; also I want to degoogle myself a bit. I'm also afraid of the direction Android is going in right now.
However, iPhones currently have so many undesirable "features" that I'll never switch at the moment. The big ones are no sideloading, crappy file manager, no Firefox+uBlock origin, and no local music player. And the 2000% storage markups on iPhones are atrocious.