This sounds like a dismissal based on a personal anecdote, rather than knowledge of what can be (and increasingly is!) done in a school. Many working in education have encouraged more interactive and project-based learning, such as PLTW[1] in STEM, and others[2] in other areas. Of course, it turns out that designing that while also teaching 6-8 classes a day to a couple hundred students is rather challenging.

I wouldn't disagree that school isn't a place for being productive, if productivity is defined as "making something people want." By that definition all learning is unproductive.

[1] https://www.pltw.org/

[2] For maths, reference the works of Jo Boaler, Peter Liljedahl, etc.; most standards I have seen in social studies in recent years have inquiry as a key component, and I know several teachers who make use of projects there; there is often agency in choosing projects in art, particularly in upper grades; and so on.