The foundational idea behind money seems to be:

Be of “value” to others, by involving in selling something. Earn “value” in return, by earning money.

Some problems are:

• This “value” earned, namely money, is often unequally distributed.

• Value to other people isn’t the only measure of value.
  For eg, Scientific Discoveries which improve Knowledge but don’t translate into direct value for other people. (I guess Research is often treated as a Public Good by Economists. Link to article: Link)

• People have often unfairly unequal opportunities to participate in value creation.

Is there a simple “solution” to economic inequality people are missing?

To study: Countries with less economic inequality, like Norway and Finland.