Depending on what you think, both choices—whether it exists or doesn’t exist—are predicated on the insistence that it is free to choose.
Discussion
I haven’t proven that nothing exists; I have only subjectively proven it for myself. The fact that it is subjective means it cannot be forced upon me. I can only interpret it and choose my stance. However, the argument against free will insists that I have no choice in contemplating the question.
This even holds true in simulation theory.
I don’t buy it personally, I’m just expanding on an idea which I come across by Federico Faggin, very interesting video for you to wrap your head around: