The main goal of VRS is to lower precision is areas that are not noticeable under general gameplay. If you have to use a 400% zoom, this proves the point. In doing this, yes, you can zoom in massively and see a slight loss of detail, but it also frees up resources to allow pushing higher in other areas. In the case of Doom, it can push higher resolution and maintain higher frame rates.
Also, the VRS in use here hasn’t been tweaked. In my uses, I’ve managed to get VRS tier 2 to work with visually no perceptible decrease in quality on oblique angles, but still have enough performance overhead to make the usage worthwhile.