What's the Role of Code Obfuscation?

It's hard to have any trust in the programs that we're running today because everything could be capable of being backdoored and then hiding those back doors. This reminds me of things I've heard about root kits that can intercept system calls when you try to list files. It's very similar to something like that where you know the backdoor is operating at a lower level for you to even be possible to detect. There have been some techniques to mitigate this with multiple reproducible builds and using different compilers and different outputs but it's all very complicated and scary.