Everyone seems to have a whole bunch of +exp gear, is there a reason for this? I've only made it to paladin but I figure that's enough to know the game, what am I missing?

easy reason: the game was different a while ago.

now: if the driver has exp gear and is on a low class, he will outlevel all the other players.. he could be lvl 71 when the other guys are lvl 60 or even less. you would have to go to lvl 80 or higher to have all others at lvl 71 (or swap the driver) all the people will have a lower lvl than the driver all climb long and use lower lvl gear which is really bad.

a few versions ago: the driver used to be the lowest class with as much exp gear as possible. all other players would keep up with his exp and all would reach lvl 71 together. good exp gear was a HUGE boost for the climb speed.

if a lower class is driving it help the higher ones to stay at the same level

Noob