Archviz on Mobile

Could anyone offer me some advice? I am working on an Archviz project and I just cant get the quality on Android that I have seen on some youtube videos such as this…

My scene on PC looks great but as soon as I switch the scene over to mobile it looks terrible. The anti aliasing is awful, the shadows are washed out, it just looks terrible.

It is obviously possible to get the above quality! My scene is setup using 512x512 textures, my shader complexity is all low. Im testing on a Galaxy S8 so have some power.

Please can anyone offer me any tips?