Contrary to popular belief, 'brand' is not a marketing discipline. Managing a brand is every employee's business, literally.
This immediately becomes more evident, when a customer-centric perspective is adopted: Imagine, for example, a customer support agent needlessly failing to resolve a simple issue for a customer, leaving them disappointed and frustrated. The customer will likely not isolate their frustration to either the issue, the unsupportive agent or the department's policies. It is much more likely that such an incident will impact the customer's perception of the brand at large.
The same is true for check-out failures, email inundation, data leaks, faulty products, tax evasion, and any other imaginable type of corporate screw up. A sufficiently disaffected customer will react indiscriminately to the brand. In the worst case, they can turn into 'campaigning brand detractors', spreading harmful word of mouth.
‘Brand’ is the sum of all perceptions a person can have about a company, service or product. And every single employee (even if they work in accounting or HR) ultimately impacts at least one stakeholder's perceptions through what they do. They are thus all brand managers.
Some companies would appoint Chief Brand- or Chief Customer Officers to influence all aspects of the customer brand experience. But these remits can be too broad in scope, create friction with other C-level officers, and even implicitly absolve other employees from taking brand building responsibility.
Basic brand building knowledge should be a horizontal skill-set, similar to basic math, courtesy, business ethics or proficient primary language skills.