What are the advantages of score-based prizes for players?
The prize for a given score is never shared. Therefore, your prize only depends on your performance. This is different than place-based prizes where things outside of the player's control affect how many people share a given prize.
The prizes do not depend on the number of entries in a section. So, a low turnout in a section does not lead to lower prizes like in a based-on prize tournament.
There is no need to wait for other games to finish to determine how much you have won. Once your game is over, you can receive your check.
Players will be motivated to play for the win. Since the total of the prizes is always higher when the result of a game is decisive, the incidence of quick draws is less.