I’ve played a good portion of the characters in the game now, and I can say with some degree of certainty that it’s no particular character that’s the problem. It’s not just Iron Bear, or Clone, or Phaseslam - it’s all of them. None of them hold up at the hardest parts of the game, all of them ultimately just become ways to proc your skills and anointments, not legitimate damage sources in their own right.
I think there is a solution here, one that isn’t just buffing them percentage-wise.
Amara, for example. Her phasecast and phaseslam’s damage, by the endgame, isn’t even capable of killing a single mook enemy. At that point, even using it in line of sight is actively bad, because it also exposes you to enemy fire while stopping you from shooting.
The solution to this is Direct Damage Transferal.
For example: Imagine if Amara had a skill that counted all Elemental Effect damage she did, and saved that number. Then, when she casts Phasecast or Phaseslam, 20-50% of that damage number was simply added to the initial damage?
Pow. Instant damage scaling. No matter how powerful your weapons are, eventually casting your action skill will be worth it, because the damage will continue to accumulate! For some weapons it might take 5 seconds, for others it might take 20, but as long as that weapon is elemental, eventually there will be a point where your action skill will do serious damage.
The same principle could be applied to most vault hunters. In fact, they tried to do this with Zane, just larger problems with the Clone in general kept it from working.
Unless this is fixed, almost all action skills will end up like Axton’s turret in Bl2; a sidenote mainly used for buffing your character, and not an interesting and deep mechanic of its own.