what are the benefit of using custom content type?

I don't see the benefit of using custom content type, since I am still
in the beginning of learning Sharepoint.

My understanding is a Content type is simlilar to a Class in OOP, pls
correct me if I am wrong.

However, when I create a list in sharepoint, the fields/columns are
also similar to the properties in a class; also another good thing of
a sp list is I can create a lookup field which is referring to another
list.

So what the benefit of using content type?

can someone clear my confusion?