I don’t see the benefit of playing multiple characters.
The only rewards for leveling alts are a 10% EXP bonus and a class mount. The mount costs 30K bronze (easy to farm), and the EXP bonus only helps if you’re leveling even more alts.
For achievements, we need to push infinite power, which isn’t warbound. Only knowledge is warbound.
I have two level 80s with 165% bonus EXP. One has 500K infinite power, the other has 150K. When I look at them both, I realize I’m just splitting my progress and slowing myself down.
The 100 world quests achievement isn’t account-bound either, so again, the game encourages sticking with one character.