Lol Conis' dad survived Enel's punishment, this indicates that his lightning isn't all that powerful.
Wiper was able to kill Enel, and pre gear Luffy hit him with a giant golden bell. This indicates that his observation haki and speed aren't that great.
Enel wasn't able to kill Luffy on any other way, he could only use his lightning, this indicates how limited his range of moves was.
And he was the most arrogant character in the show.
Lucci takes this without too much difficulty because he has superior speed, power and a way to land hits
Enel is easily the most overrated character, every decent Vice admiral would be able to take them out.