Zombies seem to be an unscientific idea.

If two creatures are physically identical, there is no way to tell whether they are zombies or not - and so nothing to discuss.

If two creatures are behaviourally identical (but physically different) there are no sensible grounds for claiming one to be more conscious than the other. One scientist could say that the one with the wetter brain is conscious, and another scientist could say that the one with the dryer brain was conscious - but they would have no way of resolving their disagreement.

Some philosophers like to discuss ideas that can't be resolved by science. They can go on about them endlessly - and there is no danger that the scientists will hijack their ideas and decide whether they are correct or not experimentally.