Capital depreciates with use, but knowledge appreciates. An idea shared with someone else is not lost but doubled. The trouble with most training programs is that they take too long. Also they are expensive. They involve time away from regular work.
Training requires instructors, materials, and classrooms.
Another drawback is that the course or seminar you need isn't on when you need it. Or if it's a convenient date, it's too far. Or the course might be over-enrolled. Suppose they cannot wait for a course to be held. Yet everyone knows the interaction between instructor and student matters.