> Say you have an int field and you want to change it to an int array field.

Will you ever do that in real life? Seriously, why would someone change something from an int to an array...

I see all these Java programmers say that you should always use getters/setters and not expose public field in classes for this reason, yet I have to see an example where this would have happened.

Also the argument that you will need to touch more files in a refactoring. Sure. Not doing so would mean adding a technical debt, a method that exists for the sole purpose of some code that you were too lazy to update. Do that and your software will become spaghetti code easily.

I see this typically Java code that is not readable for all these getters, to the point that a simple class that represent a user is like 200 lines of code long for all these getters/setters that only return or set fields of the class without doing nothing.

Is also a matter of performance (no wonder Java code is that slow), since you are calling a function for each property access (and a function call is an expensive operation, it involves jumps, you have to access the vtable for the object, set up the stack frame) where you could simply access a field in an object (a simple addressing with an offset for the CPU). Sure, a call is not that expensive. But imagine doing that in a loop and it will be a performance problem. It will make also the CPU optimization work more difficult, since you are jumping around.