OK so assume these top 62 people give all their money to the poor. 1.76 trillion is distributed among 3.5 billion people giving $502 each. the average net worth of these people goes from $500 to about $1000. 1 year later what will have happened? probably not much. These people will increase consumption somewhat, some might invest a bit, but mostly the money will just disappear.
Huge swathes of the population have minimal net worth, like many of my friends, and live happy, comfortable lives. If they had an extra $500 they would spend it quick. This isn't the rule obviously, and there is a lot of poverty, but these statements don't really quite give a true picture of the issue.