Why did the Greeks win in the Greco-Persian wars?

At the beginning of the 5th century, the Persian Empire decided to expand its possessions through the conquest of Greece. So the Greco-Persian wars began, which lasted almost half a century. The main reasons for the victories of the Greeks were:

1) Some of the policies were able to unite and assemble a single army, which was able to repulse the invaders.

2) At that time, the Greeks had good commanders such as Themistocles, Miltidates, Leonidas, etc.

3) The Greeks fought on their land and defended their homeland.

4) The Persian army was very motley, which complicated the command, it was also difficult to maintain a fighting spirit in such an army.