ok, so...

EV training is basically winning (to get EXP) and giving your Pokemon an item that raises whatever it's highest SP. stat is?
Where's the Training/Strategy?
I don't completely understand.

Let's say Pidgey has a high SP.ATK
You'd just have to give it something to raise that SP.ATK right?
Now let's say the item to do that is the best is (blabla) which Everyone can get.

Won't everyone have a Pidgey with the same stats?