Mostly it's obvious why, other newer frames, do more for "less". Armor DR rampup is a problem for almost everyone that doesn't have armor breaking skills. There's also lots of newer frames that now outdamage the older ones. The old balance got way behind.
Like I've been saying since they nerfed her, She really needs back that range. I think a 75% range nerf to WoF is not worth at all the extra energy nerf and damage buff. What good is x2 damage if the range is 5m? At that range you can kill them faster with your melee since it's in range. So Ember already has built in moderation to her WoF by the way mods effect it. To get more Strength you need to sacrifice range, and efficiency. To get more range and efficiency you need to get rid of more strength. It's self regulating in that regard. You can either have weak flames that last forever, or very strong flames that quickly eat up your energy. Or like most of the vets that used her for later stages of the game you found a good middle ground on range CC with fire quake and efficiency to endure long tracks of activity while you kill off waves of enemy between cover.
So revert her WoF to the way it was. Some of my changes are just smaller ones to the way she existed previously that would make her fair much better in the later game content.
Fireball: Get rid of the stupid charge up and the LoS blocking ball of obstruction and simply make it work like the Cat lady and wolf prisoner molotov's. Where it hit's a explosion, followed by fire on the ground.
Accelerant: Keep it the same it's her only amazing ability pretty much right now.
Fireblast: This is the one that can use some utility work. Instead of the hard to use gimick of gaining heat damage if shot through (That you literally have to crouch or it won't work due the flames being so low IIRC) Make it have a synergy with accelerant. IF the enemy is effected by her 2 they will explode and have armor shattering effects in additions to the blast proc. Due to the nature of Heat procs now getting past the armor to the bonus damage against flesh is always nice. Could also have the exploded bad guys drop more fire on the ground around them.
WoF: Revert it to the way it was, however perhaps have it changed that the further away the target from Ember the less damage it takes, and the less chance it has of getting a heat proc. Like making the Ember the source of the heat, the closer you are to it the more heat damage you take. Other wise the only major update it needs is heat damage itself.
I personally always thought she was just fine before the current changes, only thing holding her back was how bad heat was vs shields and armor especially. The ticks of DoT never updated to highest only restarted timers and so forth.