I can’t say anything about the player numbers (because as Moriala said, there is no clear counter) but if you decide to play the game I suggest you to join one of the big guilds if you want to do lots of group content.
What @onepotatotwopotato said is sadly pretty accurate if you don’t have any guild, the global chat can look really dead and, if alive, very repetitive (Chaos / WB / RF spam). Though I haven’t played for 3 or 4 weeks now and I don’t know if that changed in any way during that time.