Comparing Unreal & Eevee as render engines in animated film

I’ve followed the use of Unreal as the render engine in animated film for some time – specifically, Epic’s use of it themselves in their cinematic trailer in 2017:…ndex=2&t=2862s

Other indie filmmakers have also used Unreal this way, eg.:…&index=4&t=11s

While Unreal is capable of producing obvious quality:
… Blender’s Eevee is also capable of some great stuff too:…&index=24&t=0s

So…, can someone explain to me how Unreal’s render engine differs from Eevee in render quality and speed?

  • Are they different technologies?
  • Is one faster than the other?
  • Does one produce different quality than the other?

(I’m curious about this because if Unreal produces very similar-quality output in the same amount of time, the advantage would be to keep everything in Blender, obviously, to avoid the work involved in shuffling everything off to another application just to do rendering. If, however, Unreal offers great advantages, the work would be justified.)

As far as I know, both are realtime engines, but Unreal has interactivity, it’s meant for games but adapted to animation.
If you’re not going to use any interactivity, as Unreal is a game engine, then you would add complexity to the workflow and make things harder using it. If you’re only making animations then Eevee is enough, unless you need something especific unreal has.