So not that person, but yes and no.
Smoking is damaging to the lungs by two main mechanisms. One is that multiple chemicals directly cause cancer over long periods of time. And not just in the lungs, but they are carried thru out the blood stream, excreted in the urine, and travel down the throats and thru the GI system. Smoking causes lung cancers, but also mouth, throat, stomach, GI, kidney, and bladder cancer.
However, the direct damage of hot smoke in the lungs also causes damage. Your lungs, much like a muscle, will adapt to repeated stress. Your lungs naturally produce mucus to trap foreign particles and push them instead down to your stomach and out thru waste. This keeps your lungs a sterile environment. When constantly exposed to smoke the mucus producing cells grow in number (similar to how a muscle grows in size) and you produce crazy amounts of mucus. That's why smokers cough up mucus all the time and will eventually lead to chronic bronchitis, which obstructs the lung from all the mucus.
The lungs also have a self repairing mechanism by which they cut and repair the small airways at their base. Due to chronic damage your lungs do more cutting than repairing. While the small alveoli use to inflate and deflate like blowing up and releasing a balloon (deflated on its own), they have been damage so much that they lose their elasticity. Much like blowing air into a plastic grocery bag and it not deflating like a balloon would. This is called emphysema, another chronic obstructive disease.
Asthmatics naturally have a hyper reactive airway to irritants and will produce more mucus and their airways will constrict more severely. Any irritant will cause this such as smoking and pollution. But it is usually reversible when the irritant is removed.
While there have been no studies identifying cancer causing properties of marijuana, they are theorized to cause COPD in the same mechanism as tobacco because it is mechanical damage. Not a chemical one. But there have not been any long term research to prove this. One can theorize that vaping might reduce this damage, but again no studies have been conducted to determine this.