Simplicity
One important way to deal with complexity is to reduce it to something simpler.
Divide and conquer principle: Divide the original problem into separate sub-problems that can be solved individually.

Maintainability
We must also be able to maintain and extend the solution in an evolving world. So it is important that the use OOP not only solve the problem, but also result in a program that can be maintained.

Reusability
When you divide problems into sub-problems, you will sometimes see similar sub-problems. Then it would be nicer to reuse a similar solution.

Flexibility
It is also desirable that your software is flexible. You may for example need to deliver several variants of your software to different customers.
Or you may need to reconfigure the software to a changed context. Also some of your shared sub-solutions may need to go into contexts that are not completely the same.