You might be starting to have that understanding but whether it's correct is a completely separate question. Even if this study were proof that poor sleep is 10

You might be starting to have that understanding but whether it's correct is a completely separate question. Even if this study were proof that poor sleep is 100% causal of Alzheimer's (it's not even close), that would neither be proof that all Alzheimer's is caused by poor sleep nor proof that members of "hustle culture" sleep less. You've made about three or four unsupported inferences.