Well, I think things like physical abilities that work x times per day and the like still represent something that the characters are aware of... some effort or inner reserve or similar... so I don't agree with your assessment in that sense.
K think that for spell slots, but that's specifically because of the in-world explanation for how they're filled that a friend pointed me to in the 2e PHB that justifies them in-fiction. Most of the weird ability resource pools have nothing like that justifying what otherwise looks a lot like nonsense. But alright, YMMV.
But even if I did, what we're talking about isn't the same. We're talking about a game element... a unit of play called a turn, or something similar... that corresponds to time in the game world. The characters are absolutely aware of time in their world. So I don't think it's meta in that sense, at all.
(I answered this part last) Alright. Given the context of the rest of your post where you're saying the tasks in fiction are all the same length of time, this makes more sense. I was not assuming a fixed list of tasks of equal time commitment.
My post should have said "short rest" as one of the options rather than "long rest".
Noted.
I think what we're talking about are comparable things from a time perspective. The kinds of things characters will do in a dungeon or in a city or what have you.
I don't think I have (or have played in a game that has) such a list of same-time tasks, for acts outside of combat.
I think there comes a point where you do have to zoom out to the day... prolonged journeys make sense to do that. But when we're interested in tracking time in some way that's meaningful to play, it's a good idea to have a game mechanic to do that.
And you don't think having 24x4 (96) 15 minute checkboxes and checking them off across the day, with a pile of actions that all take different quantities of time, would fit that definition? (Or zooming out and spending awake hours per week during downtime).
And you can always make adjustments to the mechanics as needed. This room is so big and filled with items it will take two turns to search. Or this area is far more dangerous, we roll twice for random encounters per turn here. And so on.

No, they don't take the same amount of time. They can take whatever amount you think makes sense. But for game purposes, you call that time a turn.
well if the amounts of time are all different, one could be 1 turn, another might be 1/4 of a turn, another 1.5 turns, etc. That's what all different times would mean. If it takes longer to do one thing than another, it's a bigger time commitment. Different relative times per-task.
For the characters, sure... 13 and a half minutes may pass. For the players, it's a turn... which means they can search the room for treasure, but risk a random encounter. Can one turn in a dungeon be 10 minutes and then one in some other location be 18? Sure, why not?

This seems to have been a misunderstanding of what I meant. I meant each task has a different time. Not in one location the time for all tasks is changed the same way.

we definitely play very different games, but I think at the fundamental level we are in agreement.