See, if D&D were at all realistic, adventurers would rapidly be suffering from major Post-Traumatic Stress disorder. I mean, even the most hardened adventurer is not going to survive having been partially digested by a giant worm, had his face burned off, or his best friend possessed by a demon without some psychological damage. Then there's the physical toll. Even assuming cure light wounds does a really dandy job, it really ain't the years, it's the mileage when it comes to slogging around in heavy armor, swinging a sword, packing your skull with mindbending spells day in and day out. And on the way to somewhere, you would constantly be picking up an annoying little cough, or malaria, or flesh eating bacteria, or whatever, and hopefully you have a cleric who can cure disease and has plenty of spell lots. After a few years, you'd be missing an arm or an eye, most of your friends and coworkers would be dead, and your family long since devoured by spiteful mind flayers or vampires. Heroes would be famous precisely because it would be such a miracle for someone to make a living as a slayer of evil, live to some level of useful experience, and successfully vanquish a mighty foe and have a relatively happy ending after that. In the face of daily peril, battles against implacable foes with few resources at your command, you would be struggling against low morale and spiritual dissolution. And that's assuming you yourself don't get transformed by the touch of pure evil.
WFRP kind of brings that experience home.
If you don't think bored peasants and socipathic rat catchers ganging up to mug a lone orc and take his head for a reward from the local constable is funny, or that watching your Knight get ripped in half by an ogre is a "good way to go, he would have wanted it that way, if actually living to a ripe old age were not an option on the table" then it may not be the game for you.
Evil that is really evil and will kill you, cartoon violence that kills, wrestling with trolls bringing about the predictable results, getting into trouble with the local authorities over "exploring ancient tombs" i.e. grave-robbing the rich and long dead, that's the WFRP experience for you.