You dont get strong instantly from consumning protein powder.
Protein powder is just protein in liquid form.Just think of it as a pureed chicken breast or something.
It is just used to fill up the kcals/calories needed and if its too inconvenient to go buy food sometimes.You can make a shake and go out and eat later.
I dont know why people keep thinking you get strong from drinking some powder NOT the way you workout and other factors.
Its like saying you can get strong by eating cans of spinach but laze around the whole day.
This also applies to other supplements.
Oh yea btw, you dont need to buy protein powder if you are only going to do direct arm exercises like curls and pushdowns.