What are the unique advantages of Magento MVC architecture when building a site?

Magento follows PHP MVC (Model-View-Controller) application architecture.
Model View Controller design Pattern is used to keep the code modular and clean to assist in programming (keep things separate).

It divides a given software application into three interconnected parts, so as to separate internal representations of information from the ways that information is presented to or accepted from the user.

The central component, the model, consists of application data, business rules, logic and functions.A view can be any output representation of information, such as a chart or a diagram

Multiple views of the same information are possible, such as a bar chart for management and a tabular view for accountants.

The third part, the controller, accepts input and converts it to commands for the model or view.