Feedback. Speed and clarity of feedback trumps effort in honing a skill. Note that parent didn't say "no work" but "no homework". Most forms of homework give unclear feedback to the student with few ways to check work before turning it in. I cannot count the number of times in middle and high school that I got a homework assignment with poor directions that was assigned the day before it was due, leaving no opportunity to correct course - just a lot of nervous "I guess this is what they want?" Hours and hours of time wasted on a concept that I might have actually understood how to apply but not how to present in the way they wanted.
There is value in going down the deadends and figuring things out without being constantly pushed back onto the road. After all, once out of school there isn't someone to correct your course for you.
This is totally true, but to be able to do that effectively you need a set of basic skills.
The work is mostly done in the classroom.
There is also a bit of homework, but much less compared to public education or older methodologies. Everyone (students, parents, teachers) is surprised how well this works.