Educator workload, stress and burnout as well as student's not buying in and thinking SEL lessons/content is boring and/or a waste of time.
Students may not understand the concepts and see the value; being intentional and teaching SEI and setting examples can also be a barrier to students accepting and being open to SEL.
Students not buying in to it. Not enough training and staff is already spread to thin.
The emotional maturity of students can have a wide range. In one class, I can have students in 10th, 11th, and 12th grade. Meeting the student where they are in life is important. Some students have a hard time seeing past their immediate world of school, sports, friends. Helping them grasp the skills they need to be an adult in the world can be challenging.