This has been bothering me for a while. When you zoom in Safari (Mac) using the pinch gesture, the text is only anti-aliased after finishing the gesture, not in realtime. Why not?
MacOS – Why does text appear blurry when zooming in Safari until you release your fingers from the trackpad
macosmulti-touchsafari
Related Solutions
It appears not the be the case for the Magic Mouse, but with the trackpad, there is a pinch to zoom gesture also. If another finger were touching the trackpad, one finger's movement could be interpreted as a pinch.
Another option is that some part of your hand is coming in contact with the mouse surface and is being interpreted as a double tap. If you turn off the double tap gesture in System Preferences, does the problem persist?
Not sure I like it, but I think it's by design. I don't really use the zoom function, but occassionaly activate it by accident when srolling. When you zoon in, it seems to remove all navigation functions other than scrolling or further zoom operations. You need to zoom back out in order to get it all back, however due to either inertia or some other feature it's possible for you to sort of bounce in again and zoom in a small amount again, making it seem unresponsive. It's very subtle, especially as the text will render beatutifully. So, in short, zoom out, check that you have really actually zoomed out all the way, then try again.
Best Answer
Probably to give a smoother and better user experience while browsing the web. If it did it in real time all systems wouldn't be able to handle it that well.