Although the chariot was only an upper grade treasure, its usability surpassed even semi extreme grade treasures. Being inside the war chariot meant having an extra layer of protection, and this layer of protection extended to several dozens of people. On the battlefield, having an extra layer of protection meant having a higher chance of survival, and thus, higher potential of killing enemies.
Not to mention ordinary experts, even Ye Chen wouldn't be able to resist the assault of thousands of experts. If he tried to do it the hard way, he would simply be courting death.
Storing away the Golden Chariot, the two left the Treasury.