I fail to see how an operating system causes 2 or 3 decades of divergent software engineering to coalesce. That's only probable if numerous components descend

I fail to see how an operating system causes 2 or 3 decades of divergent software engineering to coalesce. That's only probable if numerous components descend from the operating system group in an architectural style that is unified, congruent, and global. That's way beyond the bounds of what we traditionally call operating systems. You are more likely to wind up with a cargo cult.