the system didn't work: they didn't discard their beliefs, and they didn't learn to read. they were just molested by catholic fundamentalists and largely left to languish in their own ignorance.
you don't see white people walking around carrying out witchcraft and sacrificing goats any more, do you? and, the reason is that they were romanized by a structure that beat the ignorance out of them. christianity has created it's own set of problems, but at least white people generally reason out problems using science nowadays, rather than superstition or tradition.
a properly altruistic approach towards the indigenous peoples of this country (and i am one of them.) is to help them get passed the limitations of their own culture, abandon their religion and embrace science. that is what i want for my own people: for us to abandon our ignorance and enter the modern world.
so, the problem with the question is that it is wrong: residential schools were not an effective means of teaching indigenous people how to read, civilizing them or separating them from their ignorance. in order to achieve that desired end point, we need to try something else - something less violent, less authoritarian and less religious.
https://www.huffingtonpost.ca/2018/09/20/alberta-course-asked-students-about-positives-of-residential-schools_a_23534319/?ncid=other_trending_qeesnbnu0l8&utm_campaign=trending