Why do we use an "initialize method" instead of a constructor.

Initialize methods are used to perform the execution of certain tasks or statements but constructors are used to initializing the objects only.

Must have been a didactic decision. First you learn something fields, about setter, about the fact that you can initialize several fields with one (initialize) method and later that there is also a constructor for this. You will come across initialize methods more often, because it is the best way in certain situations (factory).