IMHO, there's nothing inherently wrong with having a mission statement.
The fix here is that you must balance that mission statement with a well-defined set of Values as well. The mission is what you want to accomplish in the world, and the Values are the principles you plan to adhere to while doing so. The values can't just be some afterthought "check the box" exercise - they have to have significant decision-making weight in practice.
A set of (imperfect, I'm sure!) examples from the Wikimedia Foundation:
The fix here is that you must balance that mission statement with a well-defined set of Values as well. The mission is what you want to accomplish in the world, and the Values are the principles you plan to adhere to while doing so. The values can't just be some afterthought "check the box" exercise - they have to have significant decision-making weight in practice.
A set of (imperfect, I'm sure!) examples from the Wikimedia Foundation:
Mission: https://wikimediafoundation.org/about/mission/ Values: https://wikimediafoundation.org/about/values/