I think your last image looks off because of the objects and left side tiles scale. Looking to the left you can see you have some huge stone tiles, when compared to the benches which would be ok if the grout size would not be of several centimeters, which is extremely high. This with the detail level you can see on the benches creates a miniature scene effect.
I’m also interested if you’ve followed a specific tutorial for your VXGI implementation and more importantly what’s the fps on this and how do you manage the scene in the viewport?