not-a-rola Out of fear for new bloatware which would slow the device down
most the reasons come down to:
time and effort (it isnt as seamless as GrapheneOS, which is why i think more regular people should be using this OS, updating iOS can take a long while)
worried about bloatware or slowing older devices down, especially since iOS 26 and the liquod glass redesign
storage issues, considering updates can require an abysmal amount of free storage just to update, about 20gb free needed for my testing iPhone 11, its been a long time issue for users to not be able to update because of storage
back when i was an iOS user i used to despise updating my iPhone, but now on GrapheneOS i hardly ever even notice it bcuz it installs automatically in the background and auto reboots every night because my auto reboot timer is low