The reasoning behind this is fabulous, "reward longtime/active players."
I have to -1 though.
Think, if you are a new player, you come to the server, play a little, and then learn about perks. Then they do some research, "Wait, I'm supposed to play for five
years to get that?!?! No way! Next server!"
Although this is better, you could easily trick this by using redstone devices instead of AFK pools. Simply put, it'd be too easy to exploit.