Not surprised to see such things created with Unreal because they have loads of money and man power to throw at problems. But then again the 2 examples you show does not really fairly represent anything, because the raytracing demo uses super expensive Nvidia hardware that not many people can touch, the second demo also requires specific mocap hardware and there's only one character active in the whole scene. Data oriented is still relatively new, give it some time. But I would say if Unreal 4 was written with data oriented design in the first place, it would have been much better, at least performance wise. Even if it is a mixture of OOP and DOD, no one says you cannot do that. It was a lost opportunity. Working with it right now is a pain, really. After all, if the engine's performance is already so great, why did they need to spend so much time fixing performance problems in their latest releases?

If you want to see what data oriented design can do, with regards to games, you can check out Unity's lastest show of their beta ECS and Job systems. And their custom C# compiler called Burst. Essentially sidestepping the Garbage collector, compile away many of C# safety features, like bounds check, under specific conditions. While processing entities in straight array iteration fashion. All in the name of performance, undoing the damages caused in the past. I guess you know that newer generations of CPUs require effective use of the cache as well as multithreading to extract the full power out. At least Unity technologies should be applauded for trying to do that, and for trying to bring it to the mass.

I'm pretty sure that many game engines do use data oriented design to some capacity, especially those that used to run on PS3. But just because they are not available off-the-shelf, no source code to look at, doesn't mean they don't exist. Off the top of my head is Insomniac Games, arguably successful studio which is also a strong advocate of DOD.

All this is to say that there are times when even the legends hold questionable beliefs, which we should take with a grain of salt.