I could only find active demographic for steam, but ofc not all players play steam, so I'd only assume the whole population is proportional to steam's data.
V patch has doubled the steam using maple population.
Basil is still dead, most people use Nexon's forums or r/maplestory. I guess people think Basil is done for due to maple's auction function.
Again it's a mind trick since the potential system. the potential system lets players who are self-funded find their own weapons and since that spreads out the players from your sight, you'll assume that there aren't many players left, but that just makes more players want to quit since no more fm spammers trying to merchant and no more people party-questing, which means that less players are good for less dc'ing and less lag in the game.