Why do astrophysicists believe they could study the origins of the universe easier from the moon than they can on earth?

This belief is based on at least a few factors.

One is that there is very little erosion on the Moon. This is significant because research on asteroids and meteors (core samples from meteors have been examined and analyzed by recent space missions) can shed light on many questions regarding the origins of the Solar System and, by extension, the Universe.

And in the early formation of the Earth and Moon, meteors regularly smashed into them. Geologists do examine meteor remnants here on Earth, but because of erosion and the effects of life on Earth, there isn't much to see and examine. Seeing the area where meteors have impacted and looking at what is left of what crashed into the planet is an easier way to examine meteors.

On the Moon, however, this is not the case; the craters that are visible date back to that early period of creation, and a thorough examination of those impact craters would provide valuable insights into the Solar System's early history.

Here on Earth, light and other electromagnetic waves have to pass through both a lot of air (the atmosphere) and magnetic fields (the magnetosphere), each of which makes "seeing" (the word used to describe the ability to clearly see objects in space) difficult, if not impossible. This is another reason that the Moon is an easier place to study from.

There are no such limitations on the Moon. This means that telescopes built there could be much larger than those like the Hubble Space Telescope, since there is no limit to what can be built based on a rocket's capacity to carry it into orbit. Additionally, telescopes built there would benefit from improved visibility due to the absence of weather patterns, clouds, magnetic fields, and the like.

And our best view of the Universe's origins comes from being able to see clearly into its deepest reaches of space; looking farther and farther into space is equivalent to looking back in time, since light moves at the speed of light, so the farther we can look, the longer the light has been traveling, and thus the further into time we are looking.

Because the moon has no atmosphere and less light pollution, astronomers find it advantageous to study the universe's origins from there. It also allows for the installation of long-term observational instruments and allows for clearer observations and access to unobstructed cosmic signals.