Chaosmancer
Legend
A DM can always kill characters if they want to. I think what people are generally trying to express when they call 5e “easy mode” is that the game is built to generally favor the players to win more often than they lose, if run according to all the guidelines in the books.
Old-school play is often more geared towards encouraging players to try and circumvent challenges via their own clever thinking, rather than to use their stats to try and overcome challenges directly. And 5e… isn’t really built with that as the assumed mode of play. The game balance is deliberately tilted in the player’s favor with things like the target 65% success rate, and “medium” encounters being ones that a party is expected to be able to win with no deaths, even if they don’t use any limited resources.
None of this to say 5e can’t be challenging. Again, the DM can always ramp up the challenge to whatever degree they wish. But, the way the guidelines are written suggests that the design intent is for players to reliably be able to use their stats to directly overcome most challenges they face. To someone who is used to or prefers that more challenge-circumvention model of gameplay, that can feel like “easy mode” because you basically never have to look for ways to circumvent a challenge.
Most games are designed so that someone always wins, 100% of the time. Every game of Risk or Chess or Poker ends with a winner.
RPG's aren't like that, they are closer to cooperative board games, like Pandemic, Spirit Island, ect where the players are playing against the "game" and working together. And those games are always weighted (at least the good ones) so that player victory, if you know how to play, is more likely than losing. Because of course they are. No one wants to spend 2 hours setting up and playing a game, just to inevitably lose.
And the problem I have with the "challenge circumvention" model is that it is often set-up where if you aren't avoiding using your stats, you will lose. Which, is a rather bizarre thing, since it raises the question of why bother having stats? And often, if you are facing a fight you can possibly win, you will. But it is in the area of traps that you cannot fight that you instantly die with no save.
But, in my experience? That style doesn't make my player's more clever. It makes them stressed. It is a constant grind where the only reward is a lack of punishment.
To wrap this up in an analogy. I think 5e does a good job of laying all the pieces out on the table, for the players to assemble the puzzle. Just because some of the puzzle pieces don't randomly explode into acid and eat through your fingers, so you have to use tongs, except on those pieces which are electrified and you need to use a stick, doesn't mean completing that puzzle is easy. The challenge is merely different.