Half the time it does something, I don't know what I did, and I'm in a rush and so instead of sitting down and having a happy little moment I'm annoyed at having it do some unexpected, unrepeatable thing.
I have never found that the case in iOS. Anything I click / do unexpectedly I can reliably repeat the steps 99% of the time, it's why I prefer iOS over Android with apps that can modify the OS.