I wouldn't say that it's unable to make a comeback, there is still a valid use case from my experience with it. The syntax, mixed-memory model, UFCS, and compilation speed are nice quality of life features compared to C++, and it's still a native binary compared to C# and Java. So if you're starting out with a new project from scratch there's not much reason not to beyond documentation reasons. And you can interface pretty easily to C/C++ as well as pretty much any other language designed for that sort of thing, but without a lot of syntax changes like Carbon.

I imagine that the scope of its uses has shrunk as other languages caught up, and I don't think it's necessarily a good language for general enterprise stuff (unless you're dealing with C++), but for new projects it's still valid IMO. I think that the biggest field it could be used in is probably games too, especially if you're already writing a new engine from scratch. You could start with the GC and then ease off of it as the project develops in order to speed up development, for example. And D could always add newer features again too, tbh.