Why I declare everything static

Answer 1

static means that "that member" belongs to a class rather than to an object.
To declare everything static means you will not need to create objects

Answer 2

not sure.... you tell me....

Answer 3

Good question, why do you do that?

Answer 4

By using static methods only you do procedural programming in an oop language.

Answer 5

main advantage: easier to test (no need to setup complex unit test Environment)
drawback: no real oop, more like procedural languages like C or FORTRAN