Ok so I am not going to look back to get into specific of that response way back when and will focus mostly on what you quoted and what you said about it.I think you are misunderstanding what the example was meant to illustrate. This is not a matter of player competence. You don't actually have to be a doctor to state your approach to a medical emergency in such a way to achieve an automatic success, or advantage. If a player states that instead of attempting to heal someone themselves, they bring their wounded friend to the nearby hospital, then that does not require any expert medical knowledge.
Similarly, you don't have to be an expert thief yourself in order to state an approach that is more likely to get you past the guards unnoticed. Maybe your character sets off an explosive on the other side of town that draws all guards in that direction? Automatic success, there are no more guards.
I agree that the way a DM should rule this is situational. But the idea that the stated approach to an action is irrelevant to the outcome, and that time taken and resources spent are more important, I completely disagree with.
I don't care how many resources a player spends to execute their dumb plan, or how long they take to execute their dumb plan. If it's a dumb plan, it is going to fail. Either automatically, or by me increasing the likelihood of failure by giving disadvantage.
And a smart plan executed with minimum resources and executed hastily, could still be an automatic success if it's a really smart plan. Or I might grant advantage.
I do not see in what you quoted of me saying the stated approach is irrelevant to the outcome - so that appears to be a straw man for you successfully slow. Congrats. I think even in 5e slaying strawmen levels you to 3rd.
In the first bit there I referenced character competence at the task vs the players competence at the task. That is **not** the same as the approach to the solution which may change the task.
The example was stating you sneak past guards and adding wait until they are occupied as changing the success.
Your examples change the task,
"I jump across the gap" and "I walk over and walk across the bridge" are two approaches to "crossing the gap" - two different tasks.
"I treat my friends disease" and "I carry my friend to doctors" also two different tasks.
"I sneak past guards while they are occupied" and "I just walk in when there are no guards" - two different tasks.
In each case, the character "capabilities,it and the circumstances then set the difficulty at the task attempted.
Maybe the explosion causes guards to follow training, stay put, and reinforcements to go to gates following emergency training. Now sneaking past is more difficult.
Maybe taking your friend to the doctor spreads the disease along the way.
Maybe crossing the bridge openly gets you noticed.
But they are different tasks.