You aren’t understanding the law. The idea was to prevent people born after 2008 buying cigarettes.
In 2028, the minimum age to buy cigarettes would be 20.
In 2048, it would be 40.
In 2093 (70 years from now), it would be 85.
So in 70 years, with this law, smokers would basically not exist. It ages people out of smoking. Without the law, the percentage of the population who smoke will remain relatively constant as people who turn 18 start smoking.
In 2028, the minimum age to buy cigarettes would be 20.
In 2048, it would be 40.
In 2093 (70 years from now), it would be 85.
So in 70 years, with this law, smokers would basically not exist. It ages people out of smoking. Without the law, the percentage of the population who smoke will remain relatively constant as people who turn 18 start smoking.