[littlestymaar]

That it has a fatal flaw is indeed a possibility, but I don't think it could be the reason why it hasn't been invented sooner: if anything, we are detecting these kinds of flaws way faster than we used to, so it's likely that in the past it would have been produced at scale long before we found the problem, and given that consumer laws were nonexistent back then, it could have been kept on the market long after the flaw had been found, as long as it is economical enough to produce.