Part of the issue with false certainty is leadership demanding estimates which then become promises.
Encouraging leadership to let go of the need for estimates on work can be challenging, but there are several strategies that may be effective:
Communicate the value of flexibility: Explain to leadership how estimates can be limiting and how a more flexible approach can lead to better outcomes and more efficient use of resources.
Share success stories: Share examples of organisations or teams that have successfully implemented a more flexible approach and the benefits they've seen as a result.
Provide alternatives: Develop and propose alternative methods for planning and tracking work progress, such as Kanban, which focus on continuous improvement and delivery rather than estimates.
Foster a culture of experimentation and learning: Encourage leadership to experiment with new approaches and to be open to learning from successes and failures. In my experience the word failure can be problematic and so ensure that the words you are using are appropriate for the organisation.
Make it measurable: Show the leadership team how the estimates are not accurate and how it's impacting the organisation's success rate. Then present them with a measurable alternative method that can help in making better decisions.
Show the benefits of the change: Explain to leadership how the new approach can lead to increased productivity, better collaboration, and improved communication.
Ultimately, the key to encouraging leadership to let go of the need for estimates on work is to demonstrate the value of a more flexible approach and to build a culture that supports experimentation and continuous improvement.