In all likelyhood, it will never make up for the cost to the country - I once saw a detailed study on the costs in treatment, support for families, etc.
But at some point, poeple will start phasing out smoking by themselves.
Also, the black market will less likely develop, since it will remain legal. And will not change overnight.
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...
Plus we're generally less dogmatic, more able to commit little rebellions and care less about the consequence of our naughty behaviour so we may bring something to a country of robot health nuts whose sole worries in life are self preservation and tax savings.
Now I wouldnt go so far as to encourage people to smoke, it's still an annoying daemon running permanently bothering you constantly to refill the craving.
https://www.imdb.com/title/tt0751841/
Will check it out.
The average price of a packet of cigarettes is now close to AUD 40 (give or take a few $$ and up from being AUD 9 back in 2008 circa). People still smoke and chain smoke.
The question remains: do sin taxes actually work to compel people to give up smoking, or they merely benefit the state treasury?