Not even mentioning how the "worlds largest Navy" of Chinese paper boats still uses fucking ramps for their aircraft carriers, their submarines still routinely fail safety checks leading to casualties due to equipment failure during dives, and they still have a naval command structure that doesn't really know how to fight a naval conflict (then again, the command structures for the Chinese army and airforce really aren't much better).
China's first carrier was an old Soviet carrier that they rebuilt. The second carrier was basically a domestic copy of their first carrier with a few upgrades and modernization touches. Both do indeed use the ski ramp style of flight deck, which means the fighters taking off from them aren't carrying as much fuel and less munitions than they normally would so that they are light enough to actually take off from the deck, because they're only under their own power (and remember, Chinese jet engines produce less thrust than Western engines).
Their latest Type 003 carrier that was just accepted into The PLAN has electromagnetic catapults like the US Navy's Gerald Ford class carriers, but their electro cats have been plagued with problems, their flight deck design is poorly laid out for conducting simultaneous launches and recoveries which means fewer sorties per hour than American carriers, and it's using old style boilers to power the ship instead of gas turbines or a nuclear power, so it's dubious that they will be able to provid the electrical power necessary for combat operations. Using boilers also means it takes MUCH longer to get the ship underway since it can take hours or even days for the boilers to heat up enough to provide full steam pressure, whereas gas turbine engines are pretty much ready to go once you've got them going, and nuclear carriers can remain powered up even at port so they're always ready to weigh anchor.
And instead of going with a proven system better suited to a boiler powered ship with steam powered catapults, they decided to go with the more advanced electro cats purely for ego and propaganda purposes. PLAN has no experience with catapult launches at all. Going from carriers with ski ramps to electro cats is like a kid going from riding his bike at 15 and then going straight to a Bugatti Chiron the day he gets his driver's license at 16. Catapults in general are complicated things. Different planes have different launch requirements, so the cats have to be able to be set to provide the proper power output for whichever plane is up next. The US gained a lot of valuable experience and data using steam cats before making the jump to electro cats, even though they likely could have made the technology jump long before they did with the Ford class. Making an electromagnetic catapult that will launch aircraft, and making an electro cat that can launch every kind of aircraft that's used in carrier ops reliably day after day, in combat conditions, in all kinds of weather conditions, and in rough seas are two totally different things. That's why the USN took so long adopting them. They are incredibly more complex and power hungry beasts than steam cats. China skipping the steam cat stage is likely going to prove to be a huge mistake, especially since they don't yet have the ability to built large nuclear powered surface vessels with the power output required to power all the systems on the ship AND the catapults. But they did it to score a propaganda win and show the world they could make them, but did so without considering that just because they COULD make something doesn't mean they SHOULD make it. It was all ego.
And yes, their submarines are also a joke. Many of their subs are either refurbished Soviet subs, or based on Soviet sub designs. And their native designs aren't much better. They have had several accidents with their submarines that resulted in loss of life, including loss of all hands. They are also very noisy designs, including their few nuke boats. They do maintain quite a few diesel-electric boats, which can have the benefit of running very quietly when running on electric power. However, that electric power is run on batteries, and batteries need to recharge. That's where the diesel part of the equation comes in, and diesel engines are damn noisy. They basically use a pair of locomotive engines. When my dad was in the US Navy he at first wanted to become a submariner and went to engineer school, because we were still running diesel-electric subs and it was the first step before going to nuke school. After engineer school he and his buddy decided to volunteer for service in-country in the Vietnam war and my dad got put on a PBR. But during engineer school he learned to work on the big ALCO 12 and 16 cylinder locomotive engines used in American diesel-electric subs as well as many smaller surface vessels, such as fleet tugs, fireboats, etc.
And yes, the PLAN is severely lacking in their safety standards. They'll allow a lot of dangerous behavior that simply would not be acceptable in any Western navy, especially cutting corners. The cutting corners thing is a society-wide problem with China, not just a military problem, that infects every layer of Chinese society. They can be just as bad as Pajeets in that regard.
And while China's Navy sounds impressive by pure numbers, they have far less total tonage than the USN and far fewer large surface vessels. They also get that total number of ships because in a war they plan on press ganging civilian ships into military service, including ferries and even small fishing trawlers.