I understand the excitement but is this thing really that difficult to build?
No, it is not particularly difficult to design or build. But as an integral part of a first-rate carrier battle group, the expenditure of significant development funds to bring it fruition speaks both to China's ambitions for its aircraft carrier program, and progress towards those goals.
Consider that despite their carrier ambitions, France and the UK have not produced such an aircraft, mostly owing to the very low numbers of airframes that would be required to service the very few carriers those nations can afford, and the resulting inefficiency of devoting significant funds to such a project. The Soviet Union did not field such an aircraft because they did not doctrinally commit to a US-style supercarrier until very late in the Cold War, which was then never realised. Only China has arrived at the combination of doctrinal requirements and resources that have led it to replicate the United States' path in this respect.
Like building 075 LHDs, it is not a technological story, but a national-political one.