Change is a long process.
People have to gain awareness of the need to change. They then have to embrace and accept the need to change. It’s only when they accept the need to change that they begin the long journey of replacing old behaviors with new ones. Unlearning can take years. It takes thousands of CORRECT repetitions to correct a bad habit. For an athlete, that can be an entire season. For an employee, that can be an entire year. Are you willing to walk with someone for a year to see if the change is possible? If not, you are not a developer of people and are likely the lid of the organization.