In physical casinos they strictly implement the 18 years old above policy before you enter and its the ideal age for me, but in a world where technology keeps on growing kids nowadays can easily gamble online. They also have the access on games where the money is still involve so technically the age limit is not that strict when it comes to online gaming.
Does the age even hold a meaning? Should it be regulated?
Yes to both! More often than not, with age comes sense of responsibility and maturity.
This should be the main reason why kids are not allowed to gamble simply because they are not mature yet and they don't know the risk of doing it. A guidance from the parents plays an important role on this matter, we have a good culture about this thing where the parents are so strict even up to the age of 18, I just don't know the culture of other countries.