This recent paper by @llynn is relevant to the issue of cut points being misleading:
From the actual paper
Blockquote
When a RCT is used to test the efficacy of a protocol applied to a syndrome comprised of a mix of diseases (or sub-phenotypes), the result only provides evidence of the average treatment effect on the mix under test as a whole, not whether the treatment used in the RCT will be beneficial or harmful for any particular disease or subphenotype within the mix.[29] In this regard, a problem posed by the construction of syndromes, which may not have been evident to those selecting the criteria, is that if the criteria are broad enough to include markedly different diseases, an RCT applied in the study of treatment of the syndrome may suffer from amplification of the HTEs. This is a fragile state, highly dependent on the mix of the diseases present. In 2020, the pandemic changed that mix of ARDS cases in a dramatic way and exposed the weakness of generalization of RCT results to disease populations which were not sufficiently represented in the RCT and worse, were not represented at all.