Our pediatricians told us risk from suffocation is associated with bad co-sleep practices, not "just with" co-sleep (in our country, not the US, and I'm quoting "just with" because I don't know how to put that better, I'm trying to make the point that if bad practices aren't followed, the risk of SIDS is comparable to babies that sleep alone). This includes co-sleeping when at least one of the parents is a smoker, or is under the influence of alcohol or other drugs (legal or otherwise), having pillows, stuffed animals, or other soft loose things in bed, the bed being too soft, the baby being able to cover their face, etc.
But he did tell us it was safe to do this if we wanted to taking some precautions, and it worked great for us with our two kids.
Yes, sure, our two cases are anecdotic evidence, but I still trust what the doctor said, and I think you shouldn't be making blanket statements against the practice.
The truth is that SIDS is always a possibility and, to be honest, neither my wife nor myself slept well until both our kids were well beyond the age where the statistics show there's a higher chance from this (roughly 1 year old). I guess this helped make co-sleep safe, as we were always very alert (to the detriment of our own wellbeing, something I don't regret since a few years of this is a drop in the water compared with a lifetime, to us anyway).
One thing safe co-sleep requires is commitment and agreement from both parents, and a fair sharing of parental duties too.
> Co-sleeping seemed like the cheat code to getting baby boy to sleep through the night
Naturally since the baby will feel the parents close by instead of being out hunting & gathering, with himself being in danger. Or worse - parents dead, potential predators around. Evolutionary traits.
Everything has risk. What is the risk of having a sleep-deprived parent caring for a baby (holding and walking with them, driving, etc)? For some people, co-sleeping (bed sharing) largely eliminates sleep deprivation. Have you weighed those risks against each other, in particular when something like the safe sleep 7 are followed for co-sleeping?
Suffocation risk is real. Don't do this.