The knowledge was found, documented and designed with long-ago and it is most likely still perfectly suitable for purpose even half a century later. You don't even need to invent anything, you just need to find what was already invented. In a lot of cases, the whitepapers and systems of the past already have better answers than what you'd come up with without dedicating similar amounts of time to the question as they did back then.
The majority of the security problems we have with operating systems nowadays were already known about and fixed in 1970. That "half a century" figure I used isn't hyperbole.
that's also an artifact of manufactured generational warfare. younger people are taught that older peoples' knowledge is worthless because it's old. that's not a natural occurance, in a world where honouring ancestors has been the norm for previous millenia.
bad interface designs that become the norm are a result of capitalism, not of anyone's age.