Several things:
Firstly, how has this article been written without reference to Hot Fuzz?
Secondly, it’s not a bad idea. Especially considering:
If you’re 16 or 17 and accompanied by an adult, you can [already] drink beer, wine or cider with a meal.
Seems reasonable, right?
But, the major problem is that this does not remove the need for ID checks. Set the age at 16, you’ll get 13-14 year olds trying it on.
What we, in the UK, really need is culture shift where being falling down drunk is not tolerated and for landlords to abide by their license and stop serving such persons alchohol.