If you have used both static methods and objects before then I am suprised that you do not see why people use objects so frequently. Objects make it easier to understand and also maintain code. Imagine if you wanted to store some data about a person and decided that you would only make use of static methods. You would have to have some way of coordinating the use of the methods so you know which name, age, address etc. belongs to which 'person'. This would likely result in very messy code that would quickly become difficult to maintain.
Objects provide the opportunity to group data and functionality so that code is easier to understand and use. Storing a collection of person objects is much more straight-forward than creating lots of static functions that attempt to group related data for the same purpose.