There are so many different ways to make the game "deadlier" if you really want to. In addition to all the variant stuff in the DMG, you can even do stuff like just remove healing and resurrection spells from the game. Take out Cure Wounds, Healing Word, Revivify, Raise Dead etc. and all the rest. If the recovery from injury/death via magical means is removed and all recovery is by natural recovery only... then voila, your game will be "deadlier".
Or let's be honest and more to the point... the game will be "slower". Because since nobody wants to have their characters die, they will just run away and go do the non-magical recovery route for however long you've set the rules for. Then and only then will they go out adventuring again. Which is fine if you as the DM are okay with extended breaks between adventures (or even in the middle of adventures), but my guess is most DMs don't want the story of the campaign broken up like that.
And this is the problem with using Death as the "losing-state" of D&D, and why focusing on the "game" of D&D rather than the "story" is never as satisfying. The players can lose in the "story" so many more and disparate ways than they ever can in the "game". So spend more time focused on ways to ruin their lives in the campaign and less time trying to just "kill" them. Because a PC whose personal or professional life is in shambles is much more of a losing state for the player than just having their character killed off.
You want the players to occasionally "lose"? Keep their characters alive but narratively in shambles with almost no way to climb out of it.
Or let's be honest and more to the point... the game will be "slower". Because since nobody wants to have their characters die, they will just run away and go do the non-magical recovery route for however long you've set the rules for. Then and only then will they go out adventuring again. Which is fine if you as the DM are okay with extended breaks between adventures (or even in the middle of adventures), but my guess is most DMs don't want the story of the campaign broken up like that.
And this is the problem with using Death as the "losing-state" of D&D, and why focusing on the "game" of D&D rather than the "story" is never as satisfying. The players can lose in the "story" so many more and disparate ways than they ever can in the "game". So spend more time focused on ways to ruin their lives in the campaign and less time trying to just "kill" them. Because a PC whose personal or professional life is in shambles is much more of a losing state for the player than just having their character killed off.
You want the players to occasionally "lose"? Keep their characters alive but narratively in shambles with almost no way to climb out of it.
