I wonder what would happen if the car (or something similar had never been invented) and someone came out with a modern saloon today.
"It'll revolutionise personal transport but we estimate it'll kill 40,0000 people in a horrible way per year"
Like many things that are harmful in some way cars got grandfathered in (as did alcohol and tobacco) - if someone came out with an equivalent of alcohol with the same side effects it would be banned immediately as well.
In fact the UK did exactly that with the psychoactive substances laws - we didn't ban a particular drug we banned any drug with a set of side effects - largely because the chemists got really good at tweaking the underlying chemical structure enough to evade the law.
The word you are looking for is pleasure. The only types of drugs that are 100% illegal are drugs that have no purpose besides making you feel pleasurable sensations. Horrible side effects (e.g. chemo) and high chance of addiction (opioids, amphetamines, etc) and more are all allowed as long as the purpose of the effect of the drug is not (solely) pleasure.
Alcohol, and increasingly in some parts of the world Cannabis, are the exceptions (I understand both of these substances have real and potential uses in healthcare, but they are perceived as recreational). These are legal or quasi-legal only because they are both already in wide use and getting society on board to enforce a ban is difficult to impossible (depending on the society, a few do) . Tabacco is also on the list, but seems to be falling off somewhat.
"It'll revolutionise personal transport but we estimate it'll kill 40,0000 people in a horrible way per year"
Like many things that are harmful in some way cars got grandfathered in (as did alcohol and tobacco) - if someone came out with an equivalent of alcohol with the same side effects it would be banned immediately as well.
In fact the UK did exactly that with the psychoactive substances laws - we didn't ban a particular drug we banned any drug with a set of side effects - largely because the chemists got really good at tweaking the underlying chemical structure enough to evade the law.