I consider walking simulators to be in the same category as the old LucasArts-style point & click adventures.
Often there is the very reduced or entirely eliminated puzzle-solving component.
In the old point & click adventures, with the very linear story, if you can't figure out a puzzle, then you are stuck. You absolutely can't advance through the story.
With the walking simulators, if you miss some bit, then you miss a part of the overall story, but you'll still get to the end and get the big picture. And you can usually go back and pick it up if you realized you missed something.
BTW, some walking simulators I can recommend:
Gone Home - very good story.
What Remains of Edith Finch - also very good and heartbreaking story.
Tacoma - also decent.
Observation - trippy story
Return of the Obra Din - this is a bit closer to the old point & click in the sense that you are a detective, and must actually Sherlock your way through.
I wouldn't have classed Return of the Obra Din as a walking simulator, but more of a puzzler like Myst. Was great, though. I'd recommend both The Talos Principle and The Witness, along those lines.
My favorite pure "walking simulator" I've played, by a mile, is Firewatch. Haven't played What Remains yet, though.
Often there is the very reduced or entirely eliminated puzzle-solving component.
In the old point & click adventures, with the very linear story, if you can't figure out a puzzle, then you are stuck. You absolutely can't advance through the story.
With the walking simulators, if you miss some bit, then you miss a part of the overall story, but you'll still get to the end and get the big picture. And you can usually go back and pick it up if you realized you missed something.
BTW, some walking simulators I can recommend:
Gone Home - very good story.
What Remains of Edith Finch - also very good and heartbreaking story.
Tacoma - also decent.
Observation - trippy story
Return of the Obra Din - this is a bit closer to the old point & click in the sense that you are a detective, and must actually Sherlock your way through.