Is private necessary for a standalone Java app?

So, I've read through a bunch of best practices online for Junit and Java in general, and a big one that people like to point out is that fields and methods should be private unless you really need to let users access them. Class variables should be private with getters and setters, and the only methods you should expose should be ones that users will call directly.

My question is, how strictly necessary are these rules when you have things like standalone apps that don't have any users? I'm currently working on something that will get run on a server maybe once a month. There are config files that the app uses that can be modified, but otherwise there is no real user interaction once it runs. I have mostly been following best practices but have run into issues with unit testing. A lot of the time it feels like I am just jumping through hoops with my unit testing getting things just right, and it would be much easier if the method or whatever was public or even protected instead.

I understand that encapsulation will make it easier to make changes behind the scenes without needing to change code all over, but without users to impact that seems a bit more flimsy. I am just making my current job harder on the off-chance it will save me time later. I've also seen all of the answers on this site saying that if you need to unit test a private method you are doing something wrong. But that is predicated on the idea that those methods should always be private, which is what I am questioning.

If I know that no one will be using the application (calling its methods from a jar or API or whatever) is there anything wrong with making everything protected? Or even public? What about keeping private fields but making every method public? Where is the balance between "correct" accessibility on pieces of code, and ease of use?