How haven’t i died yet?

I’m 20M and i mix any substance i have, i always hear about people mixing opioids and alcohol and dying but that hasn’t happened to me i usually just pass out for about 3-5 hours but i usually mix kratom with alcohol since i can’t get opioids. I’m thinking about shooting up 20mg of oxy after i take 10 shots of vodka for the euphoric effects, it shouldn’t end me since nothing does i should be dead but no substance will end me. Sounds like a good idea for getting a good high there’s no way it would kill mf cause downers cant