Ive read a comparison between Chinese carriers and the Nimitz class. There is no comparison between launch/retrieve rate of the two. And the US catapults allow the launch of fully armed and fuelled aircraft and buddy refuelling allows longer sorties than can be achieved with a ski jump deck.
The Yanks have been doing this seriously for over 80 years, it's a skill that is hard to learn. It will take the Chinese a number of years to get pilots and crew to modest proficiency, meanwhile they will lose aircraft as the Russians still do.
