The opposite is true -- smokers contribute much more in taxes than the cost of smoking related illnesses [1], and more importantly, die younger so tend not to have the long lingering (very expensive) deaths of non-smokers.
See "The smoke screen" ("Yes, Prime Minister", 1986) for a comedic take on this.
[1] https://fullfact.org/economy/does-smoking-cost-much-it-makes...