If contemporary scientists cared about proving negatives, let alone assigning prestige to the task, then there wouldn’t be a replication crisis.

...the replication crisis is not in science

When was the last time a Nobel was awarded for proving a negative? Who becomes rich and famous for being a killjoy?

The entire premise of your retort was wrong. You should have challenged them to take their certainty to the prediction markets.

where you'll bring the goalpost next?

No need, when the defense is so lacking.

This is a common misunderstanding. The main mechanism for self-correction in science isn't about replicating or refuting findings. It's about which science survives to become the basis of other science. If a finding does not bear out, it simply will not become the basis for subsequent science. It's similar to natural selection.

The so-called "replication crisis" is overblown.

If LK-99 fails to be a useful material, it's interesting life will be over very shortly. If it is useful (and even if it's not the promised room-temperature superconductor, but useful in some other aspect), it will continue on in science, in technology - everywhere it might be useful for further investigation.

Invoking the replication crisis was a rhetorical flourish. The point is that OP’s attempt at a rejoinder about proof in the negative leading to fame is silly because the entire field does not seem to be very much interested in proving negatives.

>it's interesting life will be over very shortly.

the authors managed to squeeze 24 years of grant funding out of it