Echo doesn't make you beat something it just makes it more forgiving, and allows people a better learning curve. If you wipe to a single hit, you are not getting enough experience face on the ground. The echo allows you stay up and learning.

It also helps weakened status because many times a weaken or double weaken member is pretty much dead weight unable to get through phase changes alive.

Finally, it makes parsing and ilvl a non-issue. Taking someone at lower ilvl is risky, echo makes that redundant.