I guarantee the CTO has a much more realistic view of these projects and understands how hard it is to deliver these things successfully than the average engineer. There's a metric ton of complexity and their jobs depends much more on their ability to deliver the project at a whole without knowing all the details.
The fact is the higher you go the concerns separate. I think the army motto was "go 2 levels up". You're a grunt, you need to know what your platoon and your company are up too and what the goals are so that if you can't follow the plan directly, you can still hit the objective. This is good because no plan army or business, survives reality without changing.
In the same way, you can only go so many levels down.