Cyberpunk uses fundamentally different graphics pipelines that rely heavily on temporal information. On 720p you can already see artifacts such as fizzling, smearing and blur due to aliasing of the TAA implementation, as well as other post processing like volumetric lights that also require high resolution scenes to work properly. That is why a 540p is more detrimental to this game than those other.

https://youtu.be/C5pHpQqhmR4 3:20 https://youtu.be/mVWJPYKCMco 14:30