That's the problem with those studies - those things are usually very hard to measure. What we do know though is that alcohol and tobacco cause many, many deaths and much damage to society (British doctors' study, statistics regarding alcohol abuse in traffic accidents / assault / abuse cases). We don't have anything suggesting even near societal harm caused by illicit drugs - and most of it is related to the trade in them, rather than their actual use.
The rebuttal for that is that for certain illicit drugs, there could be two reasons why we don't have evidence suggesting their societal harm:
(1) they don't actually cause any societal harm
OR
(2) they do cause societal harm, but they are controlled well enough that these harms are suppressed to a point where data is unobtainable.
The addiction data on
heroin shows this effect somewhat, that heroin is so well controlled the sample sizes are tiny, and useful statistics cannot be obtained.
EDIT: I realise that this resembles the fallacy in Russell's teapot, but the point is neither claims can be made with certainty. If the goal is to change the status quo, the burden of proof is on the person lobbying for the change to show that (2) is unlikely. For the case of psychedelic drugs, it is not ridiculous to doubt (1) and favour (2).
While we see the death toll caused by alcohol and tobacco consumption, the relative proportion of death/harm to consumers is arguably tiny. I don't believe we have statistics to a satisfactory degree of accuracy which can show that should certain illicit drugs have a large %population uptake, they would cause less death/harm than alcohol and tobacco. I could be wrong though, I don't know enough about the literature in this area of research.
And then there's the big question of whether you even believe medical studies... I'm a big skeptic there.
You answered your own point here:
Sure, you can go skeptic about anything and get away with it, but it doesn't make for a very substantive discussion.
Anyways, the point I'm trying to make is that I (and many many others) have not seen enough evidence that argue illicit drugs are necessarily safer than alcohol/tobacco. You appear to be fully confident with this claim, but have not effectively substantiated it to convince the rest of us.