It wouldn’t matter for growing the web (mostly), but it would matter for video.
Videos (in the US) are usually 24fps, 30fps, and 60fps. To show 30fps on a 60Hz display you just show each frame 2x, if you wanted to show a 24fps video you have to do something called a 3:2 pulldown where one frame played 3x and the next 2x and the next 3x, etc.
> for example, 90
For a 60fps video you then would have to play a frame 2x and the next 1x and the next 2x, etc. Doubling the duration of 1/2 of the frame can be noticeable.