There are 2 types of games. Stacked and non stacked games. In staked games one side will get noob stomped no matter what. In these games you don’t need the extra arty so you save the PPs. If it is a fairly even game chances are that both sides know this and will use saved up PPs in order to win the game.
That means we now have two types of games: Noob stomps and arty spams.