One thing worth noting is lack of fire safety. Not only did the crystal palace burn down but also most of the similar steel and glass exhibition centres built internationally (of which the crystal palace was the first very large one)
Odd. I wouldn't expect these buildings to be an above average fire risk ...
Not only that, but construction in general operated in a far different regulatory environment.
Imagine King Charles today proposing a 990 000 square foot structure in Hyde Park. Get Design. Build structure. How hard could it be?
Today there are more voices. Queen Victoria simply decreed, and it was done. Today building the structure would be fast. Getting permission to build it would take decades (even for the King) and cost a fortune.
Savehydepark.com would be a domain in seconds.
The mulberry harbours were built in a day with scant regard to the views of the locals.