There is no evidence for consciousness anywhere in the universe except for our own subjective experience of it. If I wasn’t conscious, I wouldn’t have a clue it was even a thing.

While it’s true we haven’t discovered consciousness in non-biological systems, it’s also true that besides ourselves we haven’t discovered it in biological systems either - because there’s no way to measure it. We just assume other humans and animals are conscious because their behavior suggests it, but there’s no scientific way to prove it actually feels like something to be them. Consciousness is entirely a subjective experience.

It’s perfectly valid to claim our current AI systems aren’t conscious. We can’t know for absolute certainty, but it’s a relatively safe assumption. However, the jump from that to claiming they’ll never be isn’t valid.