Weird. FFXIVcensus says there is 15.9 million characters on all worlds (which sounds like true considering that some players have alts) but only 700 thousands of them are actually active players. A bit higher in fact since Website checks for certain rewards on lodestone, but still amount of active players is probably somewhere about 1 million.
Anyway, money FFXIV brings likely do not return back to FFXIV in a full amount. Some of them most likely goes to other projects (-cough-FFVII-remake-cough-) which means that we have budget that is lower than we could have in theory. Not like we can check any actual statistic about this, but it's definitely is not all that simple as it seems to be.