What does it allow itself?
I am and have been using this app for some time on Mac and iPhone/iPad. It syncs vie iCloud, giving accessibility rights in privacy settings allows it to access it's own folder in iCloud. What is wrong with that?
I also used to sync via OneDrive back when I had an Android phone but security measures at Microsoft now require more permissions.
On the Mac the rather poorly worded notification pops up saying, "Enpass would like permission to control this computer". This puts any number of people on the defensive as you can imagine. It is however standard behavior and other things that require this permission are Google Chrome, Google Updater, Dropbox and so on. Without this access to system file much of the functionality of the app would be lost.