How important is it to have succession planning in organisations? How does it affect on performance grid of organisation?

I think that sucession planning is important and vital in each and every organisation as this allows for internal employees to assume leadership positions within the company as they acquire the necessary skills and competencies to do so. in turn employees see this as a form of organisational growth and development. This leads to a better performance of employees because they are motivated and also  the organisation will be able to adapt to environmental changes because they have persons ready to undertake roles within the organisation.