What about Niagara, the new networking layer that powers Fortnite (especially important given all the battle royale games coming out now), temporal upsampling etc. There are loads of upcoming improvements…
In the video description that works with UE4 too apparently, that looks like a third-party tool of some kind.
EDIT: Also guys, RTX is NVidia’s technology - Epic didn’t build it, it just has an engine integration - and that’s to support other non-games businesses too. The engine has gone far beyond just games now.