This is a very reasonable drawing of a bicycle. It has a solid rear triangle, and forward swept front fork, which is an important detail for actually being able to steer the bike. The drivetrain is single speed, but that's fine, and the wheels are radially laced, which is also fine: both of those simplified details are things which occur in real bicycles.

What part is missing? It appears to have all the core parts of a bicycle to me?

A better comparison would be the monstrosities generated by older models.