Calling something an illusion is the wrong way of looking at things because everything in life is about getting at least 80-99% there — to be “good enough.” Everything therefore is an illusion by that logic.
There’s no absolute guarantee that a seat belt will save you, or that no one will poison your water supply, or that your AWS service will always be up.
Perhaps we are no longer 90% in this space due to changing political climates but we were there before.
Big vessels full of poisonous (but useful!) chemicals. Aircraft control systems. All carefully designed to be far more nines than 99% reliable - provided that the components behave according to their datasheets and how they behaved during validation.
And if it’s critical enough, that isn’t just left to chance after the initial design validation. There are continuous supply chain and acceptance testing checks that have to keep being run and managed. This is one reason the costs are higher.
There’s no absolute guarantee that a seat belt will save you, or that no one will poison your water supply, or that your AWS service will always be up.
Perhaps we are no longer 90% in this space due to changing political climates but we were there before.