It's infantilizing and dumb. Grown adults should be allowed to smoke tobacco if they so wish and smoking rates are already way down due to marketing and alternatives. Noone needs to be prosecuted.
Just see how many people already go through that trouble to source illegal drugs...
If you think taking tobacco away from consumers is infantilizing, why yes, yes it is. We are dealing with children's futures. Adults get to continue smoking, children less likely to even want to smoke as the social acceptance goes down and with that there is less and less desire to smoke. Nicotine doesn't do much other than get you addicted, no one is chasing after a pronounced high with it, people start smoking because it's perceived as cool.
I can't imagine an adult wanting to start smoking, most adults get addicted in their teens.
I think you have have an import ban, and a black market, and still see significant gains in eroding the demand. I do not think people should be prosecuted for possession, but the UK will probably make some bad decisions there, but that doesn't mean the overall policy is bad.