I've always made D&D as deadly as I wanted in all editions and 5E is no exception. I have infinite dragons who know how magic works after all. I mean, I'm sorry, but I really don't get the "5E is easy". Is it less "oops you're dead" than previous editions? Sure. I see that as a benefit not a flaw. But if you want to kill off PCs, all you have to do is double tap. Hitting someone that's unconscious has advantage and causes 2 death saves. Many creatures can take out a PC on the same turn they knocked them to zero. Running at higher difficulty is a different thread though.Veteran player here who thinks things should be more deadly. 5E is exceedingly generous with death. For your table, perhaps death is "too much" or "boring", but many find it essential. For one, death being hard reduces verisimilitude greatly. At this kind of table, the 100hp barbarian can fall 100 feet, not die, and people think it's ok. It's kind of silly!
Tons of stories have people die. It gives the other players something to RP about. Perhaps the death saved someone. Perhaps the PC acted rashly or in a reckless manner, and other PCs need to see there is -some- semblance of realism.
Does it need to be a "killer" game? Of course not. But if campaign after campaign goes by without any death, there are no hard consequences. If my players want glory, gold, land, followers, powerful magic, and songs written about them, then they need to be ready for the loss of items, friends, backstory NPCs, homes, reputation, or even their lives. There is a middle ground between Game of Thrones killer games and rainbow giggles fantasy where everyone survives and gets an award no matter what they do.
I think DMs are limiting their options if the only bad outcome they can think of is for death of a PC. Death of a PC in D&D just means that PC's story ended and you have to (get to?) write up a new PC. If people want to play happy kittens and loving puppies, I'm not going to tell them they're wrong any more than if you play D&D as a version of the Saw movies. Different strokes for different folks.