In my experience, with modern young people even incredibly slight differences is enough to ruin that compatibility. I'm talking the shoes you wear, maybe that one time you ate at your desk, etc.
It's a mindset thing. People start from a place where nobody is worthy, and then actively only notice/seek things that make them more unworthy. As in, people only notice the bad stuff, never the good stuff. You can have 99 points of compatibility but that 1 you're incompatible on tips it over - because you're only looking at that 1, the 99 are invisible.