No one knows for sure what pressures led the Huns to migrate West. These Hunnic migrations forced the Goths to plead entry to the Roman Empire in order to escape the advancing Huns. This, of course, exacerbated the increasing instability of the Empire.
It may have been a drought in the Asian Steppe that forced the Hunnic migration. Valerie Trouet, a paleoclimatologist, suggests in her research that the evidence might be in the rings of trees.
Dan Jones, in his book “Plagues, Princes and Pardons” explores the impact of climate, pathogens and technology on the development of societies. He explains what made the Huns “climate migrants”:
https://lithub.com/how-to-sack-an-empire-on-goths-huns-and-the-fall-of-rome/
https://www.newsweek.com/fall-roman-empire-tree-rings-1504740?amp=1