Question: do they still hold the world's fair

Answer: Yes, In the 21st century the BIE has moved to sanction expos only every five years; following the numerous expos of the 1980s and 1990s, some see this as a means to cut down potential expenditure by participating nations. The move was also seen by some as an attempt to avoid conflicting with the Summer Olympics. The rule may apply to all expos, or it may end up that universal expositions will be restricted to every five years or so, with international or specialized expositions in the in-between years for countries wishing to celebrate a special event. The most recent universal expo was Expo 2017 in Astana.