Why the solution that fixes the fundamental issue does not always win out?

Given a holistic solution and a specific, more logically direct solution, however much investment is required that does not require as much structural change, there is a bias towards the specific solution.

Example.

Problem:
Patient with heart disease.
Clearly caused by dietary issues and overeating.
Dietary problems caused by mental wellness issues.

Solution:
Drugs targeting the heart disease.
Short pep-talk about healthier eating.

I wonder how we can do better.