The top teams sort of do get a "prize" now.
They get income from the playoff games. This can be a very small prize and it can be a very big prize. It is based on who makes it to the final rather than who ranked where in the regular season.
The recent changes in the game have reduced the advantage the top teams get by adding scrimmages for the other teams in the league. This means ALL the teams get training time and games to play during these weeks. But only the top teams get money for the games.