game is pretty active, i even see new players in leveling areas (surprisingly often)
but its no wonder as all non-russian communities have been merged
there are many auctions running and even in the deep night therer are still players around, some because they are nightplayer and some because of the different timezone
but yes, ppl tend to "rush" to endgame and thisis the place where you see all the players then (take a look at nezebgrad/yaskers tower and at marketplace in kania)
many players in battleground and on astralislands too
(in the last time i did personal research on this matter as i was interested and result was seeing over 700 players in ~ 5 minutes just by traveling around a bit without even visiting the other capital city -
you can use addon for this purpose
)
TL DR:
i dont know what you expect from population but in allods there are more than enough players for sure