Earlier quoted context omitted.
This argument is superficially compelling but I fear that it is ultimately argument from ignorance. It is true that we don’t know everything. You even offer a fairly elaborate example of something that we don’t know whether it happened or not. It could be true. The problem here is that you offer no evidence to support whether it is true or not. Now it’s story time and instead of evaluating the studies and working wit…
The whole point for randomized trials, and much of modern statistics is to argue from ignorance. You hypothesize that maybe there's something missing, who knows. A causal boogey man. Then you design a test robust to that. One term for problems this leads to is omitted variable bias. It's not about "ooh maybe this one thing is bad." It's about "this class of problem is introduced." It's tough to make an intuitive stor…
And how do you produce a social placebo to detect such effects by comparison? No treatment is not the same as known fake treatment.
In fact, even the observational study here is quite underpowered and not multicultural. It is to be taken with a few bags of salt.