What were the reasons for the diminished role of gold in the international monetary system since 1945?

Question

What were the reasons for the diminished role of gold in the international monetary system since 1945?

Answer 1

Absence of the gold standard allows the government to print more money at will and confiscate some wealth from people by diluting the value of their money through inflation.

You can't print gold the way you can print money.  It is possible to debase gold coins by adding some cheap metals to them.  But this kind of cheating is easily detected.  And it doesn't work well as a result.

It's a lot easier for the government to print money at will than to raise taxes at will.  And that's why it made sense for the government to do away with the gold standard.