Thanks for the feedback and the compliments!
The asset I used for the office environment is QA Office
I'm pretty sure the asset previews were done in HDRP and I built the game using Unity's URP so that may have been the difference in visual quality (also my environments were pretty empty which also contributed)
And this is a list of assets (obtained from a post on Reddit) of assets that the game "Phasmophobia" uses