Creating a successful military aircraft is a massive operation. Aircrafts, as among the most advanced machinery, need meticulous construction for every small component; therefore, as a whole, they could require numerous iterations to perfect.
This isn't a major problem if the aircraft is exposed to the public because flight tests and any advances may be done and published whenever they choose.
The emergence of new aircraft is rendered much more intensive inside the realm of highly confidential military programmes due to the shroud of security necessary at every stage of the route.
Confidential aircraft have urgently maintained a mystery to remain ahead of the pack, keeping their innovations out of rebel territory, whether it's for military technology or a modern weapons package.
