> how so many organizations end up investing humongous amounts of effort rolling their own databases from scratch because none of the off-the-shelf solutions meet all their requirements. But in most of these cases, it's because some of the "requirements" were actually "nice-to-haves" and they could have gotten by fine with an off-the-shelf database, but they talked themselves into building one from scratch.

I love the term "arbitrary uniqueness" for this too. Like how different are your needs, really?