How accepted is it for GMs to “lie”?

Many GMs seem to be averse to declaratively stating any categorical untruth about the gameworld. If something that happens in a scene is not what it seems, they describe the event in terms of what the characters see and hear rather than what is actually happening. If they ever relate information directly (i.e., without using an NPC), they prefix this exposition with, "You think that…" or some other hedge-betting formula. Unless they explicitly indicate otherwise, everything they say is considered necessarily true.

As a player, this bothers me. It tips the GM’s hand. It means that any definite, declarative statement the GM makes about the game world reinforces a discrepancy between player knowledge and character knowledge. For any number of in-universe reasons, my character may have a justified belief in whatever fact the GM just told me, but I as a player know it with absolute epistemological certainty, not because of any education, evidence, or intuition, because I just heard it from the mouth of God. And when God doesn’t make a definite, declarative statement, I can tell, and my character can’t. Despite this, most of the aforementioned hedge-betting phrases—"You think that…", "You believe that…", "It looks like…"—imply that there is some doubt in my character’s mind, even if there is no justification for any such doubt!

My experience as a GM is limited, but my tentative preference is to state to the players as fact whatever it is their characters think they know, regardless of the truth or falsehood of that information—all without any wishy-washy "you think that…" unless I want to drop a hint. This does not require players or character to believe what I say. If a player can give a why their character believes something else, their character believes that instead.

This preference is tentative because I’ve heard GM stories about players who get very angry at GMs who "tell lies"… and the occasional player story about big bad meanie GMs who tell lies! Apparently, young and/or naive players sometimes even feel betrayed when NPCs relate false information. That one’s easy to rebut; every experienced player knows that NPCs don’t always tell the truth… but how many of them are comfortable with the idea of the GM himself not always doing so?

I realize that there are special cases, like illusion magic and critical failures on rolls-for-information, where this is common or even normal. I’m not asking about those. I’m asking about a GM style where, regardless of framing or phrasing, all exposition is subjective, and any information that isn’t subjective is considered OOC knowledge off-limits to roleplay.

Does anyone here have experience with this style, whether as a player or as a GM? How popular is it? How do players typically respond when first exposed to it? Does it take them a while to get used to it? Do some of them come to prefer it?