DM Narration is the new Rule Zero
The DM Narrates what happens next.
I thought it was going to be a long post, but the answer to every situation was the same. If at the end of the last session the players told you they wanted to head down the Bandit Road and you've prepared for an encounter with bandits, but then at the start of the next session they say they've changed their minds? Start the session with narration about what the characters have been doing and things begin In media res on the Bandit Road with the attack. Or just before the attack if you prefer, and at that point if the players want to change their strategy and try to head back to town, that's great. But the game starts in the situation the DM narrates at the beginning of the session.
Don't want characters dying at zero hit points? The DM narrates what happens instead. The fight is dragging on and getting boring? The DM narrates how it ends and you move on to the next thing. The system for determining if the character can swing from a chandelier and out the window onto a moving stagecoach is slowing everything down and there's only a 15% chance of success? Yes… the DM narrates what happens instead.
The players wants to know when their choices matter? When the DM isn't narrating.
The players want to know when things are happening because they "have to" to advance the plot? When the DM is narrating.
This is like a cut-scene in a computer game. Players understand when they're controlling their character and when the game is being advanced to the next section where they will once again be given control. When they have control their decisions are meaningful and the DM is being honest about hidden information, dice rolls and the game system. When the DM is narrating the players understand that to keep things moving and interesting there will be times when the DM narrates actions by the character and events that happen in the world without referring to dice rolls or rule systems.
I think that if, like me, you've decided you want to play in a game without dice fudging, illusionism, railroading etc. this is a good way to address the legitimate reasons people may have for wanting to use those techniques in the first place.