Sure. But there’s no basis for which goal should be difficult and which shouldn’t be. Which demonstrates the arbitrariness of using different ones for different difficulties.
There's no basis for which combat encounter should be difficult, and which shouldn't, either. That's, in most common playstyles, still in the GM's purview.
It’s more nuanced though, as some PCs will fail and even the same PC can do all the checks.
Yes. The point is that this is a dial the GM can turn.
My point doesn’t rely on the implausible.
You were talking about grounding in the fiction. Being plausibly effective is about grounding the thing in the fiction: Does this action make sense
in the fiction to move the party towards the goal, or not?
I’m perfectly content looking just at plausible actions. Even here, the actions should fictionally carry different weights and have different impacts.
So, this is an abstraction and simplification.
The whole point is that all successes are worth the same.
No. That is not "the whole point". The whole point is to have a technique in the toolbox that a GM can use with little prep, with just a couple parameters to tweak, that done well is more smooth, loose, quick, and open to player creativity and engagement than the typically highly-designed and prepared challenge.
That said, you were presented with the most basic version of this technique. I've found it to usually be sufficient, but if you have a bug about it, having the GM decide how many ticks one action gets you won't have the Game Police coming to drag you away or anything. You can tart it up. It won't explode.
But, as you tart it up more and more, you lose more and more of the actual point, until you are in a situation that is equivalent to running atomic, six-second rounds per normal.
What do you mean it’s not used for goals?
Read carefully. I said you don't use this for
ALL goals. Sometimes, the PCs set goals that are achieved more simply, and don't need this structure.
Similar in some respects but different in some key ones.
1. Failure for combat actions doesn’t move you closer to defeat, it preserves the status quo.
You are being a bit too strict in thinking "an action" in this technique is like one player's turn in a combat.
We can use this technique to describe a fight. But then, a success is, broadly, "you dish it out", and a failure is "you take a hit". If you don't dish out enough before you take too much, you lose the fight.
2. Different combat actions have different weights and impacts with respect to winning the battle.
Eh. Used to be, way back when, all damage was 1d6.
I already said this technique has fewer pre-specified, specialized inputs - it is a bit more abstract than typical D&D combat, but thereby allows more freeform input from your players.