Grognards are people that play old war gaming systems and complain about new things.
They're exactly the sort of person that wants to hear "play Warhammer Fantasy."
It's not gritty unless character creation includes backup/multiple characters
The Pathfinder game I'm in definitely has some of the grim dark from Warhammer. All of the PCs have at least major insanity now, most of the NPCs have a blown fuse or two also. My first character had a mental break down so bad I had to start a new character. Had to leave a party NPC behind because his PTSD was so bad he couldn't function. It's been fun times.
Might want to tell your DM to check out the Rotgrind setting for inspiration - one of the co-creators is Thurston Hillman, so it's as close to first party as Battlezoo is.
Basically people who complain you cannot make a gritty dark fantasy in style of Berserk or Game of Thrones in 5e be it because it turns PCs into op superheroes who cannot die or because there is abundance of easy and safe magic or (if they're covered bigots) because of the push for diversity in game's aesthetics and moving away from humanocentrism and always evil races...all these people would be happier if they dropped D&D and played Warhammer Fantasy.
Changeling: the Dreaming fan here. Our system is better suited to the roleplay side of things, several sessions can go by without a single combat, and it's not the core focus of the system.