Every time a notably difficult game is released, the same argument runs: should it include an easier mode, and does adding one damage the experience the developers built.
The argument is unusually heated for a question about a settings menu, which suggests it is standing in for something else.
The case against
In some games difficulty is the content. The frustration, the repeated failure, and the eventual competence are the experience, and a mode that removes them delivers something structurally different while calling it the same thing.
There is also a shared-experience argument. Part of the appeal of a hard game is that everyone who finished it went through the same thing, and that commonality is diluted when the difficulty varied per player.
The case for
Players have different amounts of time, different reflexes, and different disabilities. A game that is challenging for one person is impossible for another, and the second person is excluded from a story and a world rather than from a challenge.
And nobody is forced to use an easier setting. The argument that its existence damages a player who does not select it is difficult to make concrete.
Where accessibility sits
Distinctly, and this is the part that gets muddled. Remappable controls, adjustable timing windows, colour options, subtitle sizing, and toggles for motion effects are not difficulty settings. They remove barriers that have nothing to do with the intended challenge.
A player who cannot press three buttons simultaneously is not being challenged by that requirement. They are being excluded by it.
Where it has landed
Most studios now ship extensive accessibility options and treat difficulty as a separate design decision. Some hard games add modes, others do not, and the sky has not fallen in either direction.
Which suggests the argument was always more about identity than about design.