Outsiders don't see what happens inside companies.
A solution may need to integrate with in-house frameworks and billing (and you'll die trying to make billing simple).
A feature may get added for a big customer, and be warped by their requirements.
A feature may need to be implemented in a hurry (taking on tech debt) to win a bid/contract.
Conway's law shapes implementations - the right team to implement a thing simply may be busy with something more important, so another team will need to work around them.
In such situations the obvious simplest solution may not be available, and you either do what you can given the constraints, or fail to meet business' requirements.
Oh, I absolutely agree that there are all kinds of constraints when dealing with real world problems, including non technical ones like time constraints and expertise level. But those constraints are never documented and communicated when the resulting complex artifact is released, which causes a lot of unpleasant surprises for users. That's the reason why many engineers avoid such artifacts to mitigate the risks.
But why the true requirements are hidden?