It's say current UE4 games don't match the details of the UE4 demos they showed on release.
See this for the original demo of UE4. https://www.youtube.com/watch?v=dD9CPqSKjTU
If you want to see particle effects like the demo, skip ahead to 11 minutes: https://www.youtube.com/watch?v=ZkW_uD0PzIw&t=11m
Someone's hack of the save files: https://www.youtube.com/watch?v=sfZbFXSLLtk
I think the Decima engine would have worked better (Horizon Zero Dawn), because the bar for 'amazing' is so high. Final Fantasy 7 requires impressive visuals for its story to have impact in its original release, in all of its spinoffs, and that bar is so high now.
They describe how this is still their dynamic when they mention their goal to have Fortnite running on UE5 before they consider it ready for the masses.