Well, Windows generally doesn't search for driver update, so that's the answer to your question.
Neither do I, by the way. Only people who run programs like this seem to do. You wonder why.
1st time I run it, I went back and took down dates and build numbers of 10-15 things it listed. A couple of them changed afterward. 9 days later I ran it again, got another 10-15 drivers outdated. Again, a couple ended up with different numbers after updating. The rest didn't change, I ran the update search from system devices and it found one before compleating "IOBIt's" update What does IOBits update do that windows update search doesn't? Am I missing something?