This is just a nonsensical rebuttal. We can easily experimentally verify that jumping from a skyscraper is dangerous.

You could be the only conscious being in the universe and all of us just zombies: you have no way of knowing.

What's it like to be a monkey instead? Dog? Bat? Tree? We don't know.

No one's saying the graphics card is conscious. I could imagine the graphic cards could give rise to consciousness. But - crucially - I don't know. And neither do you.

You say you're conscious - where in you does the consciousness reside? Surely not the left pinky? What makes you you?

Normally when we debate what something is, what we are actually debating about is what it does, with the implicit assumption that the "is-ness" of a thing is defined as the complete collection of all the properties it exhibits.

As it does not seem possible to do this with consciousness, it is not possible to debate it. It is conceivable that this implies that consciousness cannot exist, but that depends on your metaphysics.

Consciousness is almost the opposite. It consists of lots of weird properties, people disagree where it starts and ends, and people very frequently get tricked into thinking things we now obviously believe are not conscious, are. There is not even a working definition, a "local definition" that works for this conversation between us. It's just complete gibberish.