Perhaps they didn’t use the right words. Iirc the correct term is ‘fiduciary duty’. A publicly traded company has a fiduciary duty to create value for shareholders.

The duties of some fiduciaries have been codified, for example, the statutory duty of skill and care which is imposed upon trustees by section 1 of the Trustee Act 2000 (TrA 2000) and the relationship between company directors and the company under the Companies Act 2006

www.lexisnexis.co.uk/legal/…/fiduciary-duties