Guys you don‘t have to wonder 3rd time in a row. We all know that CEV/FIVB works if you feed them with money.
Start wondering why all the big tournements are in China first before wondering why Turkey is hosting it for the 3rd time.
I think you meant Japan!
But it's true that some Asian nations (Japan, China, also Thailand) have the money, size of economies, as well as enthusiastic fans, and they are willing to spend big money to host those FIVB tournaments. But of course other NOC or Confederation may bid to host some international events. So really no complaint in this regard. Money and willingness do the heavy talks!