This is a "PEBCAK" issue, or in this case "PEBCAP".
You're used to Android. You know how to do things there. You like the way it works there, and how it looks. You don't want to change your habits.
Just a few issues: I am used to seeing my Alexa shopping list on my home screen. I couldn't get a shopping list on the widgets pane of iOS. I tried AnyList and Todoist. Neither allowed me to display a particular list, just the app itself and with Todoist just the basic task list. The calendar app is illogical - not intuitive to cycle through week, month, year, day, agenda. You get stuck on the year display and it's difficult to get out of it. The calendar widget is over simplistic.
Some apps have a settings menu within the app, most require you to visit the iOS settings app - which consists of a huge list of settings with little structure.
I like to have my camera and photos app where I want it on my home screen - not possible with iOS.
There is an issue with CalDAV support - I couldn't subscribe to my Diskstation calendar, yet this is possible on my Mac and on Android.
The display isn't up to Samsung Galaxy S9 standards, even though Samsung makes the iPhone display.
There is no indication of whether I am fast charging using a cable or with wireless.
There is no true multi-tasking. I could go on and on. No doubt there are workarounds to some of these issues, but as I was setting it up my heart was sinking fast. I paid £999 for which I would have expected something much better than my £700 S9 (I actually paid £469 for it in a CPW deal with a SIM-only contract which I could - and did - cancel). When I talk to iOS users it appears they don't do what I've been trying to set up - most seem to use their phones at a lower level than I am used to.