Ive never heard anyone suggest that 17 year old children need go collecting for chinuch.
I have heard multiple times that it’s important to go collecting, I believe it has to do with the fact that the kids in general don’t pay tuition and owe some hakaras hatov
17 and 18 yr olds are not colecting 5k each. They are going in groups of and 5 and if all 5 works, at 2500 per month….thats 12,5000$ – pretty good I would think.
One of popa’s brothers went in a group of two (at 19) and made about 3k from thurs to sun. And I don’t mean 3 and a half weeks… a half of a week, and seriously, you can neither collect nor work most of the month