The ideal gas model was created to summarize some laws and study the behaviour of the gases, that depends on the properties.
It is really helpful and it is the first approach to the real behaviour of the gases, because all the other equations that came out after it, they have a basis on it. Historically, the ideal gas model was one of the first and most suitable ways to describe and calculate the properties of the gases.
It is also important that it's one of the easiest ways to relate the properties that are in the model, and it's very useful under certain conditions (specially temperature and pressure).