what prevents digital holography on DVD writables from performing such computations optically, even if less efficient? imagine each layer in the computation co

what prevents digital holography on DVD writables from performing such computations optically, even if less efficient? imagine each layer in the computation consisting of a DVD + a number of (embedding dimension) light sensors and light sources (or perhaps OPA / external cavity laser setups); instead of N light sources it could be 1 light source and a ferroelectric FLCOS display like the cheap 320 x 240 monochrome high refresh rate displays in the cheap toy projectors from the past https://github.com/ElectronAsh/FLCOS-Mini-Projector-ESP32 https://github.com/ElectronAsh/FLCOS-Mini-Projector-ESP32 it doesn't sound too crazy and could permit a low entry cost to a bulky and probably less energy efficient setup, but with updates models you could just burn a new hologram on a fresh DVD and people wouldn't be tied to advanced semiconductor manufacture.