I agree with Maximum-Dev on this one - not every feature has to run on every platform. There isn’t a multiplatform game on earth that’s like that with 100% feature parity. You might cut subsurface scattering for one, or kill some dynamic shadows on another, turn off tessellation or POM, run at a lower resolution, or turn off antialiasing. The entire point of an options menu is to give the developer the ability to use higher end features without worrying about making the game unplayable for anyone on mid/low spec machines.
Not every game on Unreal is even targeting multiple platforms to begin with. For every project that even has a license to develop for console, there are 100 others that are just focusing on PC that could really benefit from at least having the option. And, if you -are- targeting consoles, there ARE console games currently that have dynamic global illumination. They’re few and far between, but they exist, and with the PS4 Pro and Project Scorpio both going to be available by the end of the year, it’s going to become a lot more common since you have all this extra power.
And, I know I’ve made this point quite a few times in the past, dynamic GI is useful for more than just the finished game. Even if you’re making a 100% baked lighting scene, there is still incredible value in being able to preview what the baked lighting might look like as you work and just bake it all down when you’re finished. For lighting, it’s a great thing to have there to work with, and potentially saves a lot of time if you end up having a lot of iterations. So even -if- I agreed with you that it’s not viable for a finished game in the end, it would still very much have a place in the editor.