People didn't invent the saying "when the student is ready, the teacher appears" for nothing.

But following that it's a fair point that how we do things is not optimal. E.g. pushing kids into classes based on their age and than having everyone for the most part do the same things. People/kids are just different, different interests, different levels. Maybe it was a necessity once, but maybe we can do things differently now.

Are you sure? I struggled for years to maintain a decent mark in french class. 2 months of duolingo for spanish and I was able to have conversations.

A grammar, written first approach is hard and boring but it does scale to 30 students for 1 teacher though.