I mean flora is destroying aura so thats not the case - Aura **REQUIRES **Aemon to be able to get anywhere near enough damage and i'd argue without the exclusive artifact its really sub par to most comps especially in the new season 3 types with corrosion and shadow.
I will also add the whole concept of aura was in blaze being badass boss killers with max hp contributions. THe max hp is so insignificant that its largely just "does blaze let me deal more damage" aka i hit 3 times with aemon. The max HP being capped aggressively makes it weak and forgettable as a feature of aura.
Narzilla's a3 is super underwhelming dealing 11k damage on a 5000 attack build up to 6 times. So her ult is only 66k damage versus any legendary hero hitting and that assumes in blaze state. Careth's passive gives you 1 40% increased ult which is really quite weak versus an overall atk up or cdmg up (you get with someone like zhorak or tolnanen passive). Theo is dealing 620% vs 800% tolnanen (thats before his passive stacks) so is severly weakened. Gerthin Battle is 490% vs Theo 240%. The aura multipliers are underpowered to make teh Blaze Max HP a thing and that doesnt scale enough.
So Aura as an archetype is designed as a dual state mechanic where maximum damage is achieved in Blaze but in reality the additional max hp makes the non-blaze multipliers weaker to support htem but are not contributing enough damage to make it worthwhile and with "generators" only existing in legendary form of Diantha or Lincos you simply cant sustain blaze in a large enough period.
Compared to IB - Nord (rare) is able generate good crystals for your DPS. In Wild you have multple epic and rare champions generating wild stacks for the primary epic dps. In rally you can have an epic buffer and multiple allies replicate and generate rally stacks. Corrosion has 2 really good epics to generate and deal corrosion damage. In Shadow - Taldie is probably better at generating shadow then some of the legendaries in the right setup.
In my opinion Aura is Weak and is in the same book as Thunderbolt. Without Perkunte/Aemon, the archetypes have incredibly weak epic and rares that simply make the entire archetype sub-par and not worth using (just like poison too to some extent).