This is a classic slippery slope argument. Losing weight is not the same thing as a pandemic like this. The two-fold reason that these measures are taken is A) over-filling of hospitals and shut-down of all non-emergency services and B) extremely high death rate. Smoking or whatever scary slippery slope you think we're on is not the same thing as the ICU's filling up way over capacity and hundreds of thousands of people dropping dead that normally wouldn't.
The idea that we should be against common-sense measures to promote herd immunity during a very real pandemic because "the government will make you stop smoking" is frankly an outrageously claim.
It's long been held, since at least America began, that herd immunity is vital to the success and security of a nation. Our militaries require these vaccinations because a fighting force must be healthy. Our schools require these vaccines because sick kids and sick cities don't learn.
The idea that a vaccine mandate is anything more than a century-old, bog-standard, completely required part of the human war against disease is a radical and anti-civilized position. Herd immunity is non-negotiable for our level of modern society to exist.
I swear, we are killing ourselves. Dense civilization requires trade offs, and in the war against pandemic disease, that does include vaccination.