I agree with the OP. I have made many levels with the old editor for COD4. It is cake. Of course the quality is not near what UE4 can do, but it did not require me to be a 3D artist, to be familiar with those programs, jumping in and out of editor to different programs to make things.
I started with UE4 by fiddling with mapping. And without the experience with the 3d modeling programs, it is next to impossible to put together anything worth a ****.
People need to remember, there is a reason why game companies have teams of people that are specific in their knowledge… small places or do it yourself people, can’t freaking know it all.
So in area UE4 has been a disappointment.