Why don't the craters on the moon eventually erode away?

Answer 1

They do, but very slowly. There is no atmosphere or liquid water on the Moon, meaning no wind, waves, or blowing dust to erode the craters. There is also no volcanic activity or tectonic action to erase them as on Earth.

Many more craters have been obliterated by subsequent impacts than by slowly crumbling away. Some craters are hundreds of millions of years old.

Answer 2

Craters on the moon do not erode away because the Moon has no atmosphere or weather to wear them down like on Earth. Since there is no wind, water, or other forces to erode the surface, the craters remain relatively unchanged over time.