No, Doom is not a final product of some sort. Going back to my "kitchen" analogy, Doom is like a recipe book - it's great for some ideation (you can check for example what kind of things used in Python module and build your own, or extend existing, 'official' module). It offers you some modularity - Doom-based configs are great for breaking down into reusable components. Doom's core also contains a lot of very nifty macros that allow you to reduce otherwise unavoidable boilerplate. Other than that, Doom is just the regular, good old Emacs - you still can do everything you could do before, with perhaps some better structure and code ergonomics.

Doom may become obsolete only if it keeps partitioning into separate packages, e.g., doom-modeline started as a core component of Doom, now it's a separate package. Similarly, nothing really preventing anyone from forking other core parts of Doom into separate packages.

Also, evil-mode keys are optional, anyone can use Doom without using vim keys, there's still good value in doing that.