No doubt there is a giant list of reasons that the playerbase is dropping
People are getting sick of the constant crashes - Most new playes don't re-connect after a server crash]
People may see the server as "P2W" - A knew a guy who before the booster packs spent hours and hours buying and selling for small profit each time, Around the Christmas update he obtained a hand cannon for over 100mil, The next day it was announced that the mega rare gifts were to be introduced in the booster packs. All he ever traded for was gone as the price dropped from 100mill to around 20mill
Zarp isn't into "Attracting new players" - Don't get me wrong Zarp DarkRP is a great Gamemode and the owners are doing a great job but I'd say the devs focus on retaining people who are allready in the community rather than attracting new ones.
Staff Team - We all know nobody is perfect and we all make mistakes, Short tempered players may deem these "Mistakes" as high unacceptable and might leave as a result.
There are probably more but thats all i wanted to post
When a new update comes out we gain lots of players. But then when it is removed the player base diminishes, so we need some more new features that are different to other servers to keep the server alive.
We need to focus on a more noob friendly experience, right now all of the item being added are far to expensive to be obtainable by new players, and a large amount of them may just give up due to how strong certain weapons are.
new player joins
new player spends a hour making a base
new player buys printers
new player gets raided buy a gang with 20 hand cannons
new player cry's in chat
new player leaves
Oh and the some of the staff team that get a little salty and go overboard with their bans