I have a friend who quit chew only to take up smoking.
The logic, which appears to be held by many, is that ingesting hot gases in your lungs precludes you from getting sick.
But in the end, he still caught long covid. When he tested for antibodies, he had none, but he had a strange t cell count.
Despite the doctors telling him that his body was somehow now immune to covid, he got the moderna shot and now he has to get a large clot cut out of his arm.
My point is, though some things are bad for you, they are probably a hell of a lot less risky than things that are supposed to make us healthier.