> We all have the ability to act at our own discretion.
That is exactly what my argument would deny. There seems to be not even an inch of free will.
> Does it really matter
100% percent yes, for example: The absence of free will forces us to stop judging people, simply because the concept of "guilt" (on the negative side) and the concept of "merit" (on the positive side) are proven to be entirely baseless. If we applied this to our culture, we'd live in a totally different world.