The tall grass ambush is a perfect example. The question that needs to be asked is, "Why is the grass tall?" After all, it wasn't described as particularly tall until the ambush occurred. The players had no chance to react to the idea that something might be hidden in tall grass until the ambush occurred.
In other words, the only reason the grass is particularly tall here is because the DM retroactively needs to justify how the party got surprised. After all, the grass could be short, sparse, or any other thing than tall. Lots of places don't have tall grass. So, why is this, specific place filled with tall grass?
Because the completely arbitrary die rolls - a random encounter roll, a perception roll failure, etc - need to be retroactively narrated in order to make the scene make sense. After all, if the ground was rocky with little or no cover, then the ambush couldn't occur.
There is absolutely no difference between the cook being in the kitchen after a failed lock pick roll and the grass being retroactively made the perfect length. The only difference is which die rolls generated the result. And, note, the die rolls are completely divorced from the narrative. The dice say that an encounter will happen at point X. The dice also tell us that it's an ambush. Nothing the players have done have anything to do with any of these things. The terrain is then rearranged around the party so that it becomes the location for an ambush.
And we all accept this. We all play like this and don't even bat an eye.
The trick is, some people really, REALLY hate it when you shine a light on what's actually occuring in the game because then all those little lies and tricks that we play on ourselves to maintain our suspension of disbelief come crashing down.
Again, it's not a difference of substance but a difference of perception. As usual. The exhausting thing is that we've been having this discussion for decades because people absolutely will not let go of their illusions.