Death is "just right" in 5e for my group's tastes. Here are some stats...
We play every Thursday night for 5 hours, and once every two weeks on a Saturday for 6 hours. That means we play, on average, 8 hours a week. Every week; since the release date of 5e. We have seven regular players (six in one group, five in the other), with three drop-in players who live overseas and return for a handful of sessions every year. Nearly all members of the group have been playing since 4e, and about half have been playing for 20+ years. We are an experienced group.
Having said that, we play it fast and loose. The players do NOT optimize for team plays. They will (sometimes) stab each other in the back to prove a point. They will rarely risk their own PC to save another PC, if the risk of their own PC dying is high. There is a LOT of ego in my group, and players will take rash actions simply to shame another PC. And... more than anything else... "retreat" and "surrender" are simply not in their playbook. If it's a fight, it's usually to the death - even if the PCs are obviously losing. Did I mention there is a lot of ego in my group?
Also, their DM (me) doesn't use a screen, lets the dice fall where they may, and plays intelligent enemies as intelligent enemies (i.e. target obviously weak PCs, keep fallen PCs down, tag-team, use ambushes, etc, etc). About the only thing I don't do is needlessly coup de grace fallen PCs. That's a step too far.
Okay, having established that background... the two gaming groups above have lost a total of 114 PCs to date. Permanent losses. Any character that is raised doesn't count in that total; only ripped-up character sheets.
So, that's about 1 PC every 10 hours of play, or so? It doesn't feel quite that lethal. The Thursday guys went 1st-to-10th level in their last campaign (4 months of play) without losing a single character, before TPKing. We always start at 1st level, and our campaigns regularly get to around 8th-12th level. The numbers are also skewed by some occasional bizarre stuff, like a player losing 3 characters in rapid succession in the same session. For example: difficult fight, fell in lava, died... brought in back-up PC, took a huge risk, fell in lava again, died... brought in a quickly-statted new PC, thought it could never happen three times in a row, fell in lava, died.
But, yeah. There's no way anyone will ever convince me that 5e isn't deadly when a group of seven players, averaging 15-20 years experience each, can go through over 100 PCs in 2.5 years. If you think D&D isn't lethal enough, your DM is soft and I feel bad for him, son. Our group has 99 problems, but running a challenging game ain't one.
Also, I keep a spreadsheet. So here's some details...
Most Prevalent Killers: Dragons (19 PCs killed), Goblinoids (11 PCs killed), Elementals (11 PCs killed)
Most Frequently Killed Races: Humans (47), Elves (12), Half-Elves (11)
Most Frequently Killed Classes: Fighters (16), Rogues (13), Rangers (11)
Most Amusing PC Death Stat: PCs killed by other PCs (6; either due to domination, accident, or outright murder)
Least Frequently Killed Class: Bard (6; either because they're hard to kill, or simply not that popular in my group)
Single Worst TPK: Tie between Rahadin (Curse of Strahd) and the White Dragon (Hoard of the Dragon Queen), both of whom capped 5 PCs each