@Joanne Yes, I think you're exactly correct -- experience matters. I've seen people on social media saying that "some PhD students are very talented nowadays". But no matter how talented they are, they still lack experience. The most important thing for an AC is to make decisions/recommendations about submissions based on their experience, even when the reviews are "noisy". I don't think PhD students can do this well, even if they are exceptionally talented. But for now, it seems that we can't avoid this, so we just have to be mentally prepared for it. Things may get worse.