Random means unpredictable/non deterministic, it does not have to be equally distributed. Normal dice throws 6 with the same probability as 1. Biased dice that throws 6 twice as much as 1 is still random, but it does not throw numbers equally

Smokers have significantly higher chance to get cancer then non-smokers, but they are not guaranteed to have it. Both smokers and non-smokers can get lung cancer and it is biased random whether you will get it or not.