Why cannot each episode be two hours long?

Why cannot each episode be two hours long? If whoever decides how many episodes to air in such a shot amount of time decides to air one hour episodes with or without at least one two hour episode, how do you expect a contestant to get through all 500 questions in such a short time. I wish all of the episodes were two hours because then we may see a contestant answer all 500 questions. Now it is looking like it may never happen. If the episodes were two hours long and aired once or twice a week in primetime, that would be okay for me because that will not burn me out. Five days a week like Jeopardy! and Wheel of Fortune are would probably burn me out.