P4p rankings are definitely pointless, as they have no physical meaning. Divisional rankings, however, affect matchmaking, as fighters tend to avoid fighting those who are ranked beneath them and strive to fight higher ranked opponents. Divisional rankings also ultimately affect the order of title contention and, as a result, fighter pay. They are a pretty important part of the matchmaking and contract negotiation system the UFC has set up and are far from pointless. Ask any fighter if he thinks whether divisional rankings are pointless or not.