That's not what dependence means. That could be an outcome. And each of those drugs has a different potential outcome from long term use.
Take for example the difference between marijuana and cigarettes. Cigarettes are much more addictive, and have clear evidence of causing lung cancer. It would seem logical that marijuana would also cause lung cancer, but there is not enough evidence to say for certain that it does.
So dependence on cigarettes can definitively kill you. Dependence on marijuana might make you less employable, but it's not certain that it might kill you.
Anyway, there is no data showing smoking marijuana causes lung cancer (rather, there is no high quality data. I'm sure some NIDA-funding scientists have found otherwise, but it's not considered correct).
The NSF review concluded that, at most, smoking marijuana causes respiratory problems, but not lung cancer. The only type of cancer positively associated with marijuana smoking was a form of prostate cancer, which happens to be easily treated.