Quite a few organizations (and most people I know) disagree completely.

My kids' elementary school in Vancouver has offered babysitting courses in some form or another for a dozen years or so starting at grade 4. They also instituted an official policy for allowing children to go home on their own at the age of 8 with annual parental signature (prior to this no permission was required, just common sense).

Many schools and organizations in Vancouver offer babysitting and "safe at home" courses for kids. Example: "11 and up" https://vancouverfirstaid.ca/first-aid-courses/babysitting-courses/

The official Canadian Red Cross babysitting course (available in many locations across Canada, including Vancouver) is specifically designed for children aged "11 to 15": http://www.redcross.ca/training-and-certification/course-descriptions/first-aid-at-home-courses/babysitting

Why would organizations offer such  courses to children if they should not left on their own?