Because this game is short. It doesn’t have many events (about 120 races including championships in the World Circuits section, even GT6 had more races), and it seems like the career mode is incomplete. There are only a handful of championships, there are no races with pitstops, no endurance races, no real specific events (Rain Masters, 4WD cup) or events unique to Gr.2 (Super GT) or Gr.1 (Prototypes) cars. It really feels like this game was rushed, and the amount of bugs this game has further solidifies this sentiment for me.