We are also blessed by our greater gravity. Thus the “escape velocity” for gas particles is lower on Mars than on Earth.
Yes, and there's that too. And, we have the moon which serves to keep Earth's axis of rotation relatively stable. And then, there's Earth's twenty odd degree axial tilt which gives us the seasons. And, to think, all of these blessings are nothing more than happenstance. (In the minds of some.)