Comment by compass_copium

As long as a researcher said "we controlled for confounding variables," there are plenty of people willing to take it at face value.

It's really difficult (maybe not possible) to do that in these large retrospective studies. Shingles vaccine preventing dementia, GLP-1 drugs preventing just about everything, etc, etc. There are plenty of good faith critiques of this kind of work from actual medical researchers making essentially the same point as the OP.