If someone is using a Mac laptop, the zooms that can be achieved using the trackpad can be very precise, however the zooms with Mouse Wheel or Keyboard Shortcuts can be a bit too "jumpy" and frustrating.
For example it jumps from 50% to 75% to 100%. What I often need given my screen size is 60%.
Maybe if the zooms were smoother all the time it would allow more users to find the right zoom for their comfort, especially if working with several screens