As far as I know, amplivolt is just electricity manipulation and the villain literally gets his electricity from a taser, meaning that calling it a lightning isn't literal nor we can assume that he's launching or discharging said electricity at the speed of lightning (which varies in speed too).
Kaminari didn't blitz anyone or react to anything either. Kaminari dashed to the front, which means that he has faster travel speed than the pros (unlikely) or the pros aren't really dashing at their full speed unlike Kaminari (most likely unless we're suggesting he's faster than Edgeshot, and we only saw him get past a couple of heroes).
Kaminari doesn't react to the electricity attaxk itself, that's never been shown, and he clearly notices the villain well before the villain ever launches his electricity attack. We only see Kaminari during the attack as already using himself as a conductor of sorts that sucks up all of the discharged electricity.
A single natural lightning bolt contains at least hundreds of millioms of volts, up to billions. Unless it's been explicitly stated that the Amplivolt can raise it to that amount, it doesn't amount to anything either.
It becomes an outlier when a lot of characters in the series are barely bullet timers and mostly flounder around supersonic range until we get to the top tiers, so suddenly giving them a ridiculously immense speed upgrade due to Navel Laser or some other beam attacks, it becomes an outlier (assuming the feats are valid or correctly interpreted/described in the first place).