I've never thought of tutoring as an "intervention", rather as complementary, but considering how ineffectively some subjects were taught to me in the classroom

I've never thought of tutoring as an "intervention", rather as complementary, but considering how ineffectively some subjects were taught to me in the classroom, I wouldn't disagree that it'd be a useful complete intervention. If you don't have access to a tutor, it's basically up to blind luck whether you're able to learn from the resources available.