The "youth" who have drinking problems usually start well before they turn 18.
Increasing the age limit won't make any difference.
They're already willing to break the law and all the current restrictions on the sale and promotion of alcohol haven't worked.

They're already willing to break the law
Shockadelic,
I think you'll find that it is more a case of the Law letting them do it. Much easier to fine the outlets or so the circus that calls itself a judicial system seems to think.
If we're so worried about all those alcohol & drug abuse crapheads why don't we do something about it like having a national Service ? Ah no, the poor youngsters wouldn't like it, let's punish the social drinkers who are behaving themselves instead but happen to be over 0.05 & perfectly in control of their senses. The only reason we have 0.05 is because most social drinkers wouldn't go past 0.06 & that would severely impact on lost revenue.

Individual. Ah 'the poor youngsters wouldnt like it'.
I have had a few unpleasant dealings with teenage girls, who are often worse than the boys of their age. I do not mention this much but put a 19 year old in hospital after she attacked me in a drunken rage. She had been drinking with friends and felt rejected when they dropped her home and was precluded from the group. Being 15kgs heavier that me she had me down and out for a while.
Said teen had a five year history of drunken rages, bashing strangers and a bit of a hero status. Was dealt with by the law with short term results. National Service or boot camp, something along these lines could nip these behaviors in the bud.
Often these kids have been over compensated for whatever reason. Have no respect for anything or anyone. Sometimes parents are to blame, their daily surroundings contribute,and sometimes kids go off the rails and leave good parents baffled as to why. Intervention has to be easier than the alternative.

Many young people believe in the erroneous assumption that one has to drink to excess, whether it be by binge drinking, or drinking over many hours , so as to enjoy oneself. This misconception is likely to be the result of inadequate upbringing or peer pressure, and consequently it takes time for those people to change their ways, if at all.

Therefore, Governments need to spend more on education to reduce the adoption of such misconceptions , rather than hoping to deter irresponsible drinking by legislating for harsher sentences for offenders.

If gun happy America is an example of restricting booze to 21years old or over, then I don't think we should bother.

LOL, a glass of cold water and a good lie down for Suseonline who is going off again.

On no account allow her anywhere near crackers or surgical spirits.