Might want to check my updated post mate lol. They literally specify that they do not, in fact, do other things. I'm not the one guessing, you are. Do you work for Arrowhead?
Dlss is a hardware graphics layer and is not implemented more than calling an api.
As is almost everything in game development. DLSS is an ENGINE feature. It has to be implemented by the engine team. The people making art for the game aren't implementing DLSS or ray tracing lol.
At arrowhead especially, since they literally tell us on their website, the people doing DLSS would not be doing content or art or music or anything other than engine features.
The people that would implement dlss work on content for the game, as I said. Content needs programming. How are you months into not understanding this very simple fact