Completely agree with the OP. New Rage is just about useless and I don't pick it up anymore.
Even if a character pools 6 AP, it doesn't help. Crits only cause 50% more damage by default, meaning after spending 2 AP, you have 4 left and you get 6 AP worth of damage due to the guaranteed crit.
But, you still had to spend the memory on Rage, and you still lose 100% dodge and resistances until the next turn, and you gain no benefit from any critical damage you had.
Sure, if you also use Adrenaline or Flesh Sacrifice or have a high boost to your Critical Damage stat you can actually get some damage increase, but it's a lot of work to get an actual use-case.
The ability should be high-risk, high reward, but instead it's almost always high-risk and 0 reward.
I actually liked all of the older versions of rage, even though were too strong, because they were fun. Also, I still don't like that when Rage is active all critical strike Stat becomes useless.
I think a flat % damage boost for Rage would be more appropriate than a guaranteed Crit. It would also make the ability work on Backstabs.
I really liked the old option of debuffing enemies with Rage too. It made the ability much more flexible, and made it useful for mages too.
I hope Rage gets a buff or else it will be almost entirely unused. I'm not sure if that's worse than being overused, but at least the ability used to be fun.