That goes for all cathedrals though. Just two random examples, Notre Dame took about 100 years for the main structure, Cologne Cathedral took 600 years.

https://en.wikipedia.org/wiki/Notre-Dame_de_Paris

https://en.wikipedia.org/wiki/Cologne_Cathedral

And is usually a matter of funding, famously Hagia Sophia was built in five years

Crazy Horse Memorial has been dragging out too. Got the impression that what exists now is functional enough to serve as a tourist trap so there's less incentive to complete it.