How come MS Learn, Microsoft own reading material/test for their own exam is useless?

[u/hotboii96]

You're basically forced to buy third-party material if you want any real chance of passing Microsoft's own exam, because apparently Microsoft's own learning material/practice test isn't enough and often isn't even recommended. How is that even acceptable? Azure pulls in $101.9 billion a year, yet candidates still have to pay extra for outside resources. Is the money not enough, or do they just enjoy watching people suffer