Why it feels bad to play a traditional ADC against this champions (Warning : Not adc main)

I will be honest with you, i'm not adc and i barely able to master and at some point in aram only.

Anyway here is the things that i keep notice when i play with this few ADC in aram.

The traditional ADC : etc. As you can see their theme mostly depend on pure AA that build damage over time "slowly" and if we talking about common builds they goes with etc.

While on other hand we got non traditional ADC where everyone got a their own theme of gameplay or powerspikes hidden within kit or just very very powerful AA damage. Example : etc

So here come my question why it always feel bad and useless to play such traditional ADC in ARAM or in lane?

I will list 3 things i keep notice in lane phase(early game in aram) and late game that make non traditional ADC better than traditional ADC :

1. it feels like traditional ADC have much more cost on their ability and in the return they take no direct reward from it unless it very late game while non one traditional early and late game cost little mana and give alot of reward in return.
2. Lifesteal/SpellVamp/Whatever you call feel so so much rewarding on the highest burst damage of non traditional ADC while traditional ADC take ages to build healing, for example late game vs she just destroy him even if he started the fight with like 1 second early damage cause she can just burst him in seconds and able to out heal his damage while he can't make enough damage to out heal her damage or kill her before she sustain.
3. Burst damage, traditional ADC make slow building up damage and ofcourse non traditional ADC just do assassin damage from range which is beyond my mind limit of thinking, how such damage allowed on ranged champion that isn't burst mage and able to even able to melt down tankers.