@Health
Wikipedia is not a credible source.
I grew up in a large city whose BOE is NOT elected.
Boards of Education hire the Superintendent, but do not micromanage the schools. Superintendents are generally contract employees and tend to outlast the terms of the BOE.
Our town’s new Superintendent has a three year contract, the BOE is elected for a two year term. The term is up in 2021, the Super will be here until at least 2023.
BTW, our BOE is split 1/2 R, 1/2 D