If earth was not tilted on a axis, we wouldn't have any seasons. we wouldn't have seasons because the axis tilts us towards or away from the sun, and if you're tilted torwards the sun the sun you would have summer. if you're tilted away from the sun, you have winter. if there was no axis, the temperature would be the same all around the earth, so therefore we would not have seasons.
hopefully this helps
Because it gives it more space to be able to move farther and faster which can change the speed in which you want it to go
