The Wasteland is full of miserable creatures you're probably better off than. No (usually) sentient creature is quite so sorry as the Ghoul, however. The radioactive rascals may be nearly immortal -- many of them can remember the mediocre-old-days before the war -- but it's a trade-off. Ignore the bad skin, raspy voice, and rotting flesh. Ghouls have to contend with a social stigma brought on by years of lazy game design, and their own, mindless cousins. To put it bluntly, everyone thinks they're zombies.
To be fair, most of them come pretty close. Slow radiation exposure has baked their brains as well as their bodies. These crispy cannibals make up the majority of Ghouls in the post-war United States. There are exceptions to the rule, however.
Intelligent Ghouls once dwelled in Vault-Tec's own Vault 12. Unlike most Vaults, which experimented on a closed population, 12 had an outward mechanical flaw that allowed scores of unapproved citizens to seeks shelter. That is, the door never shut properly. The unsealed sheltered protected the panicked populace from the worst of nuclear Armageddon. Though it couldn't, as you may have noticed, protect them from radiation poisoning.
If The Enclave and Brotherhood of Steel are the pinnacles of post-war technology Super Mutants are its biological peak. Impossibly strong, immune to radiation, and sometimes even hyper-intelligent the Super Mutants are the perfect life form for a world that just isn't meant for humans anymore. Unfortunately, they didn't have a say in the matter.
Unlike Ghouls, Super Mutants were created intentionally. Another of Vault-Tec and The Enclave's late-game gifts to humanity was the Forced Evolutionary Virus, more commonly called FEV. Nonconsensual volunteers (as well as the protagonist of the first Fallout if they weren't careful) would be "dipped" into this sickly green soup. The result was usually the ham hock with a brain we call a Super Mutant. Unfortunately, that brain wasn't especially large unless it came from a "pure" subject. Namely, kidnapped Vault dwellers who hadn't been ravaged by the wastes.
From there, Super Mutants were manipulated, mind controlled, and enslaved by whoever had the power to quell them. That didn't ingratiate them to "normal" people, who didn't understand how little control they had over their actions. After many long, bloody, and likely avoidable conflicts -- most notably with the Brotherhood of Steel -- most Super Mutants eventually found peaceful coexistence with humanity. They'll very likely outlive most of them, too, if the Wasteland has anything to say about it.