Let's say for whatever reason, opium and alcohol switch places historically and instead of alcohol being the dominant legal drug, opium derivatives become legal.
Like alcohol, the dominant forms of opiates that remain legal are low-concentrate varieties, such as smoking opium or low-strength tinctures -- in the same way that beer and wine are popular, although like spirits, morphine or heroin also exist, but are consumed mostly diluted cocktail style. For the most part, opium is sold in regulated stores and always in well-known concentrations by a well-regulated industry.
Society has recognized for centuries the problems of opium use, but as its deeply ingrained in culture only the US ever tried to ban it during Prohibition which was a complete failure. Alcohol is seen as much worse, and society is presently engaged in a "alcohol crisis" fueled by over-prescription of therapeutic alcohol and black-market alcohol which is tainted.
Would we more or less be in the same place we are now, kind of turning a blind eye to the dangers of opium -- relying mostly on the culturally ingrained "rules" for to not overdose regularly?
It seems to me that most people ignore the large-scale problems with alcohol availability and despite cultural acceptance it's probably way more dangerous than we ever consider. Millions of people are alcoholics and millions more are borderline functional alcoholics and there are vast social problems associated with alcohol, like drunk driving, violence, domestic abuse, etc.
I think there have been attempts to quantify the risks associated with the various varieties of psychoactive substances and almost always alcohol and tobacco come out 1 or 2 with opiates further down the list maybe behind barbiturates, which society mostly has avoided as a long-term crisis or black market drug.
The latter is kind of interesting considering the popularity of Seconal and Quaaludes in the late 1960s and 1970s -- it's somewhat surprising that with the surge in illciit lab-made fentanyl and other "research chemicals" that there hasn't been a parallel surge in illicit lab-made Quaaludes or Seconal.