According to various studies and world inequality report 2018, large portion of world's wealth is concentrated in the hands of small portion of population, while the bottom 50% holds less than 2%. This distribution of wealth is highly unequal and cause of concern for many people, as it contributes to social and political unrest all over the world.
What governments can do to make it more equitable?
It's probably much worse than you portray actually and the wealthier are getting even richer every year. A large chunk of that 80% will also reside in the hands of more like 1% of people and below. It is truly obscene how much wealth is wasted in the hands of a few, but unfortunately well regulated capitalism is very hard to achieve. There are a few super wise countries who had politicians with the foresight to use their resource wealth well, like Norway for example, where the profits of oil development went into a sovereign wealth fund for the wider public to use - instead of being sold off as a one off bump to government accounts like many countries did with their oil rights.