Why does light frequency affect the energy of electrons ejected in the photoelectric effect?

The frequency of light affects the energy of ejected electrons because light is absorbed in discrete packets of energy called photons, rather than as a continuous wave.21

According to Albert Einstein’s interpretation, the energy of an individual photon is directly proportional to its frequency, expressed by the equation $E=h\nu$, where $h$ is Planck’s constant and $\nu$ is the frequency. When a photon strikes a material, it transfers its energy to an electron. To escape the surface, the electron must overcome a minimum energy barrier known as the photoelectric work function ($\psi$ or $\varphi$).213

The maximum kinetic energy (${ϵ}_{max}$) of the ejected electron is determined by the difference between the photon's energy and the work function:
$${ϵ}_{max}=h\nu -\psi$$
Because the work function is a constant property of the material, any increase in the frequency of the incident light directly increases the energy remaining for the ejected electron.213