A lot of non-accessibility apps use the accessibility features to do things like window resizing and clipboard management. Looking at my relatively pristine MacBook Pro's settings, I've got Flycut and Rectangle (expected) and less expectedly Dropbox and Aquamacs with accessibility access.
I think (but could be wrong) that it's a relatively low-risk permission to grant.
Even "simple apps" can improve their UX with it like a translator app that you can summon with a global keybinding.
There just seems to be lack a convention around telling the user why the app might need those privs. Users don't even know what accessibility privs do.
I think (but could be wrong) that it's a relatively low-risk permission to grant.