Tobacco kills 8 million of its users, annually. Why is their presence in ICU beds not a topic of concern?

you can't smoke inside anymore (honestly, nowadays you can only smoke outside and at your own place, and even then, some rentals prohibit smoking) -- that's was a "mandate" to decrease smoking related diseases.

It's a significant topic of concern, and governments have been restricting the tobacco industry more and more since the 80s. Most developed countries now ban indoor smoking and the advertisement of tobacco; some are getting ready to ban tobacco outright.

I will think because it is not contagious and does not affect the global economy as such

Probably because that number is fairly stable over time. Beds exist for that load. A new load is a problem, because staffed hospital beds take time to create. It takes years to make a new nurse or doctor, for instance.

Why can’t we just group antivaxxers with smokers then?

We’ve ignored the obesity problem for a long time and are taking 0 steps to correct after we’ve seen our health systems buckle in no small part due to it. If you’re in favor of mandates but not forced weight loss you’re just playing politics.

Yes, one is easier than the other, but the magnitude of good done by reducing obesity dwarfs the good done by vaccines. If the US had ignored Covid and focused solely on obesity we would likely have been better off in terms of all cause mortality.

Nobody knows what is causing the obesity epidemic, unfortunately. There are a lot of theories but no smoking gun.

I'm not buying that. Sure there might be some unknown metabolic factors at play, but it seems disingenuous to overlook the ratio of calories consumed to calories expended.