Smoking was believed to have started 5000-3000 B.C. in Mesoamerica and SouthAmerica. It arrived in Eurasia in the 17th century. Frenchman Jean Nicot (NICOTINE) brought tobacco to France in 1560. The first report of an Englishman smoking was a sailor in Bristol in 1556.
Bloody crackpots. What a stupid thing to do.
Ah, hindsight!
No-one could genuinely have known the dangers of what was done as a relaxant and social bond until historically very recently. Far back enough, deaths from lung-cancer by smoking might have been rare because most people did not live as long as we do, even if they survived culling by any of umpteen diseases we can now prevent or cure.
For many who did die of lung-cancer, the cause might have been related to work - by inhaling toxic fumes or dust over many years.
Some thought smoking was a horrible habit. The 17thC King James wrote an anti-smoking pamphlet I think titled A Counterblaste to Tobacco, railing against the simple unpleasantness of the foul-smelling smoke. That at a time when personal hygiene was somewhat rough and ready, and towns must have been under a foul miasma of human and animal manure and decay smells mixed with smoke from inefficient household fires.
Until the link to cancer was established, even many doctors smoked, and some thought it beneficial.
Humans have always loved to do things that are bad for them!