That is crazy. J-20 showed up 2009, officially in service by 2017. But LRIP started way before that. That is 8 years and country in a less developed status than now. J-50 is spotted 2024, and 2032 is the conservative estimate of 8 years.
Didn't we get the first glimpse of the J-20 only at the tail end of 2010 / early 2011, which makes it even more impressive?