ehhh ozai generated lightning just as quick and with greater volume and zuko countered that shit fast, it was also a surprise attack lmaoHere is Azula using lightning.
Here's Mako.
Anyone from Aang's time gets fried before they even know what's happening.
But, again, Mako himself is just an average bender during his own era and gets owned by everyone. It's just that 70 years is a long time.