The biggest problem with traditional schooling is having a set curriculum based on the child’s age and expecting all children to study and progress through that material at the same pace and each attain optimal results. It just doesn’t happen. It won’t happen.
The first thing which is appreciated about the Montessori environment is how all the materials and subject matter moved from the concrete to the abstract. The child is able to interact with concepts and ideas rather than simply memorize facts.
There are no gold stars in a Montessori environment. No grades. No “Look how smart you are!” No reward for learning other than the intrinsic joy the child receives when they discover something new or realize they’ve acquired a new skill. (When Montessori does praise, it’s very specific. For example, “I like how diligently you’re working on your penmanship.”)