I think we need to look back at the OP.
If you were limited to one EDC item.
I am not likely to carry a locator beacon with me to the store, even GPS would be an unlikely pocket item.
Lighters and small pocket knives are in the pocket trash class.
So is a bit of string or wire, a few bandaids, a button compass, and a host of similar items.
From there it moves up to a personal FAK and the BOB levels.
The point that at least one person made about when and where you are makes some difference, but as EDC I think in general terms, and then modify what I do actually have to the situation I am expecting.
If I am boating on a lake I want a life jacket, if I am driving in the desert I want full water jugs, but neither of those make it as EDC
The OP never said it had to be "EDC" carry. They said " If you had to choose just one item to carry on you for a real-world lost or stranded-type situation, what would it be?" and then later mentioned their "EDC knife" and "EDC lighter", and an "EDC ... flashlight, compass, or paracord."
When I hike/camp - I bring my PLB. When I drive outside my local suburban area - I bring my PLB. My PLB is my #1 survival tool - no doubt. It can turn a real bad lost/stranded life-threatening situation into just a bad night waiting for help.
You can't call PLBs high priced. Heck, excellent PLBs are now actually cheaper than most mid-to-higher-end GPSes ... and look how many people have GPSes. PLB prices have hit the main-stream.
Regarding a knife being item #1. Like I said earlier, that is what we're supposed to say, but in reality, if I'm lost or stranded, what are my priorities if I find myself lost or stranded? As someone already asked, it depends on where I'm lost or stranded AND it depends on the weather. So, at least for me, the most likely is to be in a remote heavily or moderately forested area in midwestern U.S. spring/summer/fall (that's when I'm out camping/hiking).
So, what are the priorities? ...
0. Prevention ... oops, I'm lost or stranded, so its too late.
1. Health - mitigation of traumatic physical, environmental, or mental damage or risk.
2. Personal Protection - from temperature, wetness (rain, dew,...), insects or other wildlife, sun, fire, ...
3. Signaling - fire, light, mirror, whistle, smoke,...
4. Sustenance - water in the short term, food in the longer term, nutrients in the even longer term
5. Location & Travel - compass, map, GPS
So how does a knife help #1? If doing surgery maybe. Maybe for scraping off bee stings. I can tear clothing for bandages.
What about #2? Building shelter? ... there's usually lots of dry wood I can snap off. Cutting firewood? ... there's usually lots of dry wood I can snap off. The reality is that in heavy or moderate wooded remote areas there will be plenty of dead wood that can be broken by hand (or leg). Even in the moderately used Boundary Waters - lots of dead wood breakable by hand.
What about #3? Cutting firewood? Did that. Creating sparks with a fericonium rod? Though I haven't tried it, I'm under the impression that even a rock should do that. A mirror? A really really shiny knife might work - but its not likely. A whistle? OK, you might be able to carve a whistle with a knife - but I wouldn't know how to do that.
What about #4? Will a knife help me gather or sanitize water? Not likely. Will it help me gather food? Maybe.
OK ... this post is getting too long. You get my thinking.
Yeah, I carry a knife (mini Mk1) almost everywhere (excluding the shower, swimming pool, some schools, county court house, airport, airplanes, ... ), but still there are other items I'd select to carry first (PLB, GPS w/ electronic compass, fire, shelter, whistle, light, whistle, ...).
Just my opinion.