TLIK: Who is talking about taking tzedakah for oneself. These bochorim are not collecting tzedakah for themselves. They are collecting tzedakah for *others* that need tzedakah.
That is inarguably a humongous mitzvah. And something every child would do well being mechanech on.
And the motive is primarily chinuch. I’ve seen many times kids and young adults collecting tzedakah for tzedakah worthy individuals and organizations *other* than their own yeshiva. When I was a child P’eylim came every year and gave out pushkas and booklets to all the children (aged 7 years old through beis medrash) in the yeshiva to collect tzedaka for them. And they raised large sums. And the money did not go to our Yeshiva, it went to Eretz HaKodesh. And it wasn’t on Purim time.