I'm not sure what your point is here. You're trying to make some kind of reductio ad absurdum argument about what, statistics in general? Causal analysis is bad

I'm not sure what your point is here. You're trying to make some kind of reductio ad absurdum argument about what, statistics in general? Causal analysis is bad because causation is complicated at the intersection of social science and medicine? All models are wrong and therefore all models are useless? The primary absurdity here is that the author didn't even do an acceptable correlational study, yet presented a specific and strong causal conclusion. The author failed to establish any causality for anything at all, other than weakly ruling out Covid as a notable cause of excess death in Germany. The author's hypothesis is that people being cold (due to high energy prices) is the cause, but they absolutely do not manage to establish even the faintest hint of a valid causal argument to support that hypothesis.