I think that is exactly what I was getting at before. More experienced people know when to turn back even if the map says „well beneath your limits“. Lesser experienced people (I work at an outdoor retailer shop, I meet them every day) will often just pull through until they call for rescue or worse.
And there are cases that might even bring experienced mountaineers into a rescue situation: just imagine for an afternoon stroll you ascend a technical route up a mountain where you know you can’t reverse the moves without a rope. The descend is marked T4, so you’re looking at maximum second grade UIAA, usually secured by fixed ropes. You didn’t bring a rope, because of T4. Now imagine there was one mapper at play who forgot to mention an exposed 5m section of III+ scrambling. You might now find yourself in a somewhat precarious situation… Rescue by helicopter is usually covered by insurance in such cases, but I can imagine a clever lawyer at an insurance company might try to find out what led to this situation. (I know I’m exaggerating here)
If you’re interested I’ll attach two articles by the joint alpine clubs magazine mentioned before. The first one is a pdf in German, so non German speakers would have to utilize plain text translation.
This one is their take on OSM primarily, found here
The second one is about incidents where online route suggestions were at play, some of them based on tracks generated off of OSM routable paths found here
Aaah yeah, I get you now. And I think so too that it is hard to understand. Especially from a sport climbing perspective where most people will end up when researching UIAA grades. I fell for this too, before understanding that UIAA I-IV is not really a linear scale of the overall difficulty including the ability and reasonableness to place gear for protection.