There is probably some truth to what you're saying, but also keep in mind that tobacco contains more active compounds than nicotine alone, including MAO inhibitors in the form of harmala alkaloids. These can synergise with nicotine and make it more addictive.
Also, I'm dubious about your claim that most people need breaks, or at least any more than vapers do. I was a smoker for over a decade. I don't remember ever feeling like "that's enough, my throat hurts". It's just that smoking was triggered by the onset of withdrawal, which begins after about an hour, and becomes urgent after maybe 2-3 hours. So I'd typically smoke at an interval of 1-3 hours depending on how convenient it was to do so. And cigarettes are expensive, so that factors into it too.
Sometimes though, especially when drinking, I could chain smoke for a couple hours straight while hanging out in a park with friends, especially in the summer.
After I switched to vaping though, I have at times ended up puffing so enthusiastically that I've made myself nauseous from the nicotine. So there's certainly a limit there too.
Edit: another interesting thing I've noticed. Nicotine withdrawal seems much less severe after I switched to vaping. It takes several hours longer to become noticeable, and also feels less intense. When smoking, it took me 1 hour to start craving a cigarette, by 3 hours I'm becoming irritable with strong craving, and by 5 hours I'm extremely irritable, light-headed, and the only thing on my mind is smoking, completely incapable of focusing on anything except how to get some cigarettes and how to get to somewhere I can smoke em.
For vaping, it takes me maybe 7-8 hours to get to the 3 hour mark for smoking. I certainly get cravings long before that, maybe starting at 2-3 hours, but I'm able to push it out of my mind much more easily, for much longer. I don't know why this is. My theory is something to do with the lack of MAO inhibitors. It's also possible that it's a pharmacokinetic phenomenon, but that seems counterintuitive. If I'm ingesting higher doses of nicotine compared to smoking, blood levels will take longer to go to zero. But then I should also have higher tolerance, and therefore a higher threshold for the onset of withdrawal, since tolerance and chemical dependence are more or less the same thing.