My understanding is that essentially all of the risk of cosleeping comes from parents who are one or more of morbidly obese, alcoholic or drug abusers. Got sources that say otherwise?
Here's one (small) study that says cosleeping is safer that an separate room:
It's all official health advice from government bodies which say it's unsafe regardless of the parents situation.
I've found though this debate is similar to the "anti-vax" one, in that most people are quite emotional about it regardless of evidence, and can't generally be persuaded.
The current recommendation where I live is to sleep with the baby in the same room but in their own bassinet or crib for the first six months. After six months they can move to a separate room. So it is possibly the case that co-sleeping is safer than a separate room at that age but more dangerous than same room, separate beds.
It seems selfish to me to put that kind of risk on your own kid.