T28D, it sounds like you are thinking of flying training as it sometimes used to be, where the instructor exists mainly to protect the student from himself until he becomes competent to fly solo. (Or herself, she).
From personal experience, with good instruction a sim is good for
- recognising, setting & maintaining the correct attitudes for normal cruise, powered or glide descents, normal climb, turns etc;
- looking out prior to & during turns while maintaining the correct attitude;
- precisely adjusting attitude when changing configuration;
- pressing right rudder when increasing power or reducing speed, & vice versa;
- doing checks & drills while maintaining lookout & attitude.
Students really can get more from sim + aircraft than from just aircraft, providing good instruction is provided. It certainly isn't unsupervised playtime by any means.