It depends on the campaign, the party level and the enemies.
Hags are so ugly that their spells can kill frightened players, intellect devourers have the "body thief" ability that allows them to substitute the brain of the PC and take the body of the character, and there are enemies that can deal you Massive damage that can kill you instantly. (When damage reduces you to 0 hit points and there is damage remaining, you die if the remaining damage equals or exceeds your hit point maximum), some spells like "power word: kill", "Phantasmal killer" or "disintegrate", etc
But yeah, in general terms, it´s harder to die in 5e due to several tricks and the rules about death and dying.
Sc: https://5e.tools/bestiary.html https://www.dndbeyond.com/spells