I think that's a bit strong. I can see how someone could interpret it that way, although they would be wrong to claim it was RAW.
I think it's more accurate to say that the game mechanics are not chronological, and are separate to the fictional narrative.
As for the "teleport dodge", The rules are non-specific about what can and cannot be a trigger for a readied action, and therefore there is no "RAW" answer, it's always DM's call.
Actually, the rules are fairly specific, and much better than in previous circumstances: "First, you decide what perceivable circumstance will trigger your reaction." So it cannot be technical, it's something that can be perceived by the character.
Where I'm with you (and where
@Maxperson has trouble with in both counterspell and this example) is that by the very definition of the game, what a character perceives is just limited to what the DM tells him he perceives, there are no rules about this, just limitations (of lighting, for example) but for the simplest case, we can assume that they don't apply in the general case.
However, I would rule that "swinging a sword at me" is not actually the attack - the character could be feinting for example. Ergo, the character could teleport when the sword swings, but the attacker has not used up their attack, and could attack someone else, even moving first if they have any movement remaining.
See above, it's absolutely fine to either tell a character that he does not perceive the intent of attack or even the attack itself depending on the circumstances, and for example, even though in the general case I would allow a character to perceive that an attack is being launched, I would not allow him to do so in darkness for example.
After that, the advantage of this is that it allows a large flexibility from the DM's perspective, although I would not allow people to feint other people without some sort of skill use and possibly contested check and/or use of a (bonus ?) action mechanic. They might be competent, but their adversaries might be even more competent.
But in any case, it was not my point here, because I don't even need it for my purpose in this thread which is to show that a readied action can interrupt and negate another technical process. It drifted off to the attack process because I thought it might be easier, but actually the other one has been solved before. But in any case, as demonstrated by Deflect Missile (it's even better than shield because it's not magical), it shows that it is possible to interrupt the attack process and actually to change its outcome through a reaction, negating the attack.
It's the negation that is important here, not the specific because, as I think we agree, these depend on what the DM allows the character to perceive, my only concern is that it should be fairly consistent.