China isn't building nuclear carriers (the USN carrier fleet is all-nuclear for the foreseeable future), which gives a massive strategic advantage to the US (since a conventionally fueled carrier has to be refueled every few days, you can cripple it by taking out its supply line). Add to that the various electronic gizmos and the accumulated knowledge of what works and what doesn't, and 50 years is definitely reasonable. Now, it's not going to take the Chinese 50 years to catch up if they choose to, but in that time, there will likely be further advancements from the US side (some of the stuff that's going into the Gerald R. Ford-class carriers is off the hook).
Understood on the nuclear thing, I can see how that makes a huge difference to the effectiveness of a carrier.
On the electronic stuff, I was a little concerned, seeing as China manufactures a huge amount of the worlds consumer electronics and the average modern day small fishing trawler has more computer power than a fifties aircraft carrier, I'd be surprised if they were more than a decade behind surely?
(Of course, even if they are bang up to date on technology the point on fueling means they're still a good ways back.)
The most important element on a carrier is its air-arm. If you haven’t got the right air frames on board or the experienced naval aviators, then you’re not going to be particularly effective. The Chinese naval aviation programme hasn’t begun yet. The idea that they’d fly against the 7th Fleet over Taiwan in a few years time for example, would be ridiculous. NATO standard pilots flying aircraft a couple of generations out of your league? Turkey shoot.
You cannot start a carrier programme from scrath, base it off an ex-Soviet hull and expect to be anywhere near the standard or technology of a USN CVN or its escorts.