put another design for the start, redo the whole system of arcade, make ticket, coins from arcades tradeable. fix the issue for illegaly spawning exo and all the items, fix the level of gst, make the server less laggy, and make the players feels they are playing the graal they discovered in 2010-2016.
before fixing levels and small things, try to think another way, try to think about all the things i said and the gameplay experience, im probably sure if you do most of those things and specially the last one, players will come back. Since 2017, i feel i played a commercial game, i remember when i started this game, i was very hyped and everytime i came on i was enjoying it a lot, since most of the administration staff comes from 2010-2015, try to see what you can improve to make it looks like before, i hope i was clear enough.