I tried a iPhone 12 pro for a week between getting rid of my Oneplus 7 pro and buying the S21 Ultra when it was released and it was the notifications that really pushed me over the edge, the setup of them just made no sense coming from Android.
That and the fact some apps like Whatsapp looked like some weird DOS command line version in comparison.
It's a shame as the hardware, battery life and size of them is nice but I've been fully in the cult of Android for at least a decade and can't deal with change in my old age