I remember in the 70s when it became fairly mandatory for non-profits to have boards. The narrative was that managers and staff of the organization usually lacked all manner of business expertise and acumen that a board of volunteers could provide. Of course hierarchy still being the sacred cow of the time, and still is to an amazing degree, there was always an awkward and many times toxic relationship between the executive director and the board chair.
The whole dynamic grew worse over time as executive directors and organizational leadership became more competent and board members became not always welcome or useful advisors.
In this world, organizations benefit greatly from weaving and growing rich expert resource networks of all kinds of volunteers who can participate in all kinds of strategic and programmatic projects and efforts. This allows us to question the validity of traditional boards.