I’ll have to disagree with you - since this is not particularly true everywhere. You’re forgetting that teenagers are also people - they have needs and wants. This doesn’t necessarily mean they have a whole family to support but maybe themselves, their hobbies, or even other things that dont mean the whole family is in financial trouble.

Self reliance is an important topic within teenage years, and supporting teenagers while they become less financially reliant on parents is important. At the end the objective is to support themselves, and buy whatever the hell they want without judgement.