Traditional grades don't give any feedback on what students know, understand, and are able to do.
Unfortunately, traditional grading just reinforces fixed mindsets in students. Students labeled as "smart" due to being able to accumulate the most points will often not attempt tasks that they feel might cause them to lose their "smart" status.
Conversely, students who have internalized the "not smart" or "dumb" label because they cannot or choose not to do things to collect points shut down in this system that doesn't report learning.
Our traditional, standardized system that assumes all students can learn the same thing at the same time and assumes all learning can be reduced to choosing one answer is broken - and needs fixing.
Learning needs to be measured - not point collection.
We have to give ourselves as teachers and our students permission to change the system to one that is learning-oriented.