This game doesn't automatically cap your fps I believe, that's why vsync is required. So that it caps your fps at 60

Basically time passes on frame basis. If you allow the game to run at 120 fps animations will run twice as fast as 60 fps. VSync basically gives all players an even playing field.

The game does attempt to limit fps to 60 even on higher refresh rates, but it still ends up running slightly faster than 60 (my steam fps counter bounces between 60-61 when my monitor is at 144hz, occasionally reaching 62), and I am fairly certain would alter the game physics a bit, though I haven't tested it in a while.