UK plans to pass law banning anyone born after 2008 to buy cigarettes

I haven’t decided how I feel about this yet. But what I am wondering is: what will the consequences be if this law is passed, assuming no scope creep or other foul play? While I do think less smoking would be good for society overall, I am concerned about potential increased harms to a minority group that grows their own tobacco. Do people “overdose” on nicotine? I don’t smoke, but as I understand it, cigarettes usually have a “filter”, right? What are the consequences of not having one? I would rather people not use drugs, especially ones that affect others (like cigarettes do by way of secondhand smoke and making everything smell awful), but in the event that they’re going to anyway, I’d at least want them to do so as safely as possible. When people make drugs at home, I think there tends to be much greater risk for additional harm that could have been prevented by regulated manufacturing.