Is it true that 80% of the world's wealth in the hands of 20%?
What I read is different from yours, it was claimed in that article that the wealth of the world is being controlled by 5% of people which I agree more than yours because it's evident around us, 20% (1,577,600,000 based on the 2021 world's pollution of 7.888B) is much. However, statistics fail, yet a near representation is often regarded as valid.
What governments can do to make it more equitable?
Government can do nothing about this as wealth is being distributed by God and luck. But government can try to eliminate the monopoly and dominance of some players in some sectors and empower citizens where they could through awareness, creative teaching, grant and others.