The thing is you seem to forget about everything else Fragger has. His frag grenade is infrequent, sure, but it can kill anyone that isn’t Rhino and has a massive AoE compared to Nader’s and Fletcher, which means you are getting a free kill, even two, three or a teamwipe every 17 seconds. People are calling him to be nerfed because he has a 17 second nuke, not the other way around.
He also has 20 more HP compared to Nader and 30 more compared to Fletcher, that means he can survive one or two more shots or can still be alive after getting bombarded with explosives whereas both Nader and Fletcher would be long dead, especially if Unshakeable comes into play.
He also has access to one of the most broken weapons in the game, the BR16.
To play devil’s advocate, what advantage does Nader have over Fragger? 5 eggs instead of one nuke, sure, she can spam it all day long, and she is definitely better at breaking Aura/(Turtle) camps in this regard. Unfortunately she can only use SMGs, and sure the Crotzni is powerful, it’s no rifle; it fails over longer distances. And the Lactic-40 doesn’t work in close range like Fragger’s nades. And 20 less HP means she dies quicker; you may say it’s only one less shot compared to Fragger so it doesn’t matter, but it does; more often than not I have escaped with a silver of health left as Fragger, had it not for the extra HP I would be long dead.
And Fletcher? He has 10 less HP, which means he can take even less punishment. He can spam stickies, sure, he is broken in that regard even, but his primaries are limited to shotguns and the Blishlok which means his range is also much limited (granted the Blishlok does have a good range.) His stickies cannot bounce off walls which means he need direct LoS to his targets to do anything, more often than not if you are not sticking balls on people then it’s wasted, and sticking it in people’s face is no easy job.
You are simply not playing him to his full potential.
TL;DR: git gud.