Like the red book audio CDs that preceeded them, white book VCDs were a way to make playback a light-weight task on very specialized (maybe even single-purpose) hardware.
That's not necessarily a meaningful goal these days, but our limitations were different back then.
It's about as gross as regular Red Book CD audio. Sacrifice error correction for capacity. Errors in either audio or video streams are non-critical (to a point) and can be masked on playback. That's what C1 and C2 error correction does. There used to be copy protections that played silly games with error correction to foil CD audio rippers while not affecting playback on normal players. Think it was called Cactus Data Shield. It was not very effective.
And similar to VCD disks, the *.cda files Windows shows on audio CDs also aren't real.