This heavyweight syntax has nothing do with OOP. No common definition of OOP (before Java came into existence) said that functions cannot exist outside of a class.

Java choose to adopt object oriented purity in a very weird way. Sun has initially rejected the idea of standalone functions (static import was introduced in Java 5, closures in Java 8 and compact source files/instance main is only coming now). Even with static imports and compact source files, there is still a class holding these methods behind the scenes (for practical and compatibility reasons, more than to achieve any ideological or theoretical goals at this point). That seems like Sun was trying to keep the purity of "everything is an object", but at the same time they've introduced primitive values, which are clearly not objects. This was a pretty bad decision in my opinion. There is no practical benefit from requiring every function to be defined inside a class[1]. On the other hand, being able to have methods defined on an integer is a pretty nice feature.

If we look at a Smalltalk, which is generally considered be an example of a "pure" OOP language, we see a striking difference. This is Hello World in Smalltalk:

  'Hello, world!' printNl

[1] https://steve-yegge.blogspot.com/2006/03/execution-in-kingdo...

> Smalltalk allows you to freely define functions outside of classes

Please show an example.