I don't know the country you are from but in my country alcohol and gambling ads are almost the same and both even have billboards boldly published in public, in comparison, alcohol is way more safer than gambling because even though it is written to use both responsibly in their ads, it is so rare to see an under 18yrs taking alcohol but in gambling an under 18yrs can gamble without being noticed even though it is strictly for 18yrs and above. now, To answer your question, alcohol has been around for so long and that is why it is more accepted than gambling.
I have every reason to disagree with you on this assertion. Both alcohol and gambling are safe when done moderately and responsibly, and they can also be very harmful when abused, so invariably, they've both got same as one effects on an individual, depending on how they are approached and you'll be wrong to claim one is way better than the other. even if I'm to choose which one is better than the other, I'd even say gambling is better because gambling addiction can only mess up your finances, which could be rebuilt and regained with time, bit alcohol addiction will not only mess up your life but is also capable of influencing a person's behaviour negatively, leading them into making impulsive decisions. Plus, it's also capable of damaging your vital organs too, so how exactly is that better than something that is only capable of damaging your finances and maybe your relationship with people around you.
Alcohol and gambling can be very addictive for people who lack self control, that is why a lot of negativity is attributed to both. In my country alcohol and gambling adverts are in strategic locations for many people to see them, they're both also online and on TV. If I want to compare between gambling and alcohol the one that is more harmful and it's addiction can be very damaging than the other I'd say that it's alcohol. Gambling addiction will make you to be broke and always emotional but alcohol addiction will mass with your mind, when you're under it's influence, it takes control of your senses. Alcohol addiction can cause many health challanges which gambling addiction cannot cause.