We’ll, what to say? First, in the beginning “wealth” was also defined by productivity. But then, those who brought in the most food., provided the most security or produced the most, strongest, most intelligent children became the top of the communities they lived in; the kings and queens.
Today, the same applies, though the definition of what is productive has expanded to reflect the times. Things you want or need are the products of the most productive; a smart phone, food at the snap of your fingers, a great new album, whatever cool thing someone else has that everyone wants…!
That reality is, always has been, and always will be a result of human existence. Some are simply more productive than other. That being the case your “fair” distribution of wealth would have to be repeated frequently because those with $3mm will likely use it to out produce those with less. They’ll create, develop or build something everyone will want, if it is worth just 10 cents it will cause 10’s of millions of $$ to flow to those people. Allow this to persist for a few years and you’ll have wealth disparity all over again.
So repeated redistribution becomes necessity….…a principle theory of communism.