No? I think we are going to get into an argument about what a hit point is again, but this has in my opinion never been true. Regardless of your view on the "meat spectrum", D&D has always maintained that no Player Character ever takes the full force of a blow except when they are reduced to less than zero hit points.
("Again"? Have you & I argued about this before?)
Last night, a PC in our party was mauled by giants and a dragon until he was unconscious and dying, he fell from a height that would kill anyone (but took no further damage), then he was magically revived, got hit in the face by the dragon's fire breath, and ended the fight on his feet. For plausibility of survival, I'd rate that about a zero.
On the other hand, I've had a Shadowrun character get killed in the first round of combat because he (and I) carelessly put him in a position to get shot at. In Traveller, it took us days or weeks to recover from injuries. To me, these games feel a lot less survivable than D&D.
Barring some recent innovations, only with magic?
Yes, in fantasy games we pretty much always have a cleric or other magic healer in the party. That has a huge effect on survivability compared to games with no on-demand healing.
It's not the "guns" that are the problem. You can use a variety of techniques to mitigate bullets the way you mitigate battle axe blows, from being really dodgy to declaring it was only a flesh wound. It sort of works if you squint.
No, the problem is the M2 Brownings and the 155mm artillery shells and their high tech equivalents. Sooner or later you have to deal with the "elephant gun" problem, which is, if a handgun can kill a humanoid in a few shots, then there exists some weapon that can kill an elephant or a tank or Godzilla in a few shots. How do you model that in such a way that PC's aren't just randomly squashed?
I don't see that as any different from the problem of why low-level D&D parties aren't insta-killed by dragons. The game is arranged so that doesn't usually happen.
In the campaign I'm working on, there are BFGs that could annihilate the players. (
@Woundweaver you watching?) Some of them, I expect the players to avoid. Others, I don't know what will happen; but my friends are smart, they'll probably figure it out.