That's mainly just namespacing. The only point to use an Object in object oriented programming is to unionize objects and state. To combine them together into a single primitive. This combination breaks compose-ability.

Static functions avoid state. You put them in an object in java because java has to have everything in an object. In any other language these would just be top level functions namespaced into a package or something. You are basically using java in a more functional way. Which is fine.