More can be written, but there have been a good number of discussions about this.

I think the best summary for the rise and fall is an answer by /u/DerProfessor at "When did the worlds fair stop being a big thing and why?" . Also "Rewatching Modern Marvels (an old favorite)"... by AlviseFalier.

For the decline (they have not ended), you can also see "What happened to the World's Fair? What caused it's decline in popularity and general loss of grandiosity?" by /u/TheEmperorsNewHose and /u/FalterFire , though because it is older, there's a lot of fluff to wade through. There's also "Why did world fairs stop being a big things?", with interesting answers by GravitasIsOverrated, NeedsToShutUp, and MrDowntown.

This is not to discourage discussion. More questions, data, and debate are welcome.