Honestly, I think they are exactly as powered as they should be. Balerion is pretty much god, I easily won Aegons conquest. As it goes for the other younger dragons it is even stated in canon lore that they aren't as powerfull as they were in the earlier version. In the Queen and Princess story, the Targaeryans made great effort to recruit the Lords Paramount. Armies was also the reason why Aegon managed to "win" even though he had many fewer dragons than Rhaenyra.
They only had two more dragon's than the other side, and treachery of two blacks to the greens side didn't help. Aegon also had the older stronger dragon's like Sunfyre and Vhagar. Armies were only important because both sides were even matched with Dragon armies not because dragon's were weak.
Not really. Dragon's were basically artillery and only really effective in wide open areas, like the Field of Fire. The Dornish Rebellions, Faith Rebellion, Dance of the Dragons and the Storming of the Dragonpit are all great examples of ineffective dragons.
Not really,
The Dornish got a lucky shot in the Dragon's eye and killed it. That's just luck that saved them.
Dance of the Dragons was Dragon vs Dragon you can't say Dragon's were ineffective when they are fighting themselves. lol If only one side had Dragon's I'm sure it would have been a short war.
Storming of the Dragonpit is a laughable example. You want to say Dragon's are ineffective against armies when they are chained down inside a building? lol