It's fallacious to argue that something must be true because some you think a bunch of people agree with your position. It's irrelevant to what the rules in the book say.It's funny how you can't even provide ONE SINGLE SOURCE justifying your claim when I have provided you with all sorts, from the rules, to the devs, to well-recognised authors of advice. There's even one on this site, and although it does not pretend to be exhaustive about what affects surprise, it certainly does not say anything about characters not having their PP on.
So no, the "until it's not" does not exist elsewhere than in your own game. That's fine, you can play any way you want. Just don't claim that it's the standard way of playing.
Ah yes, "group's," that word that could be read in the "natural language" you claim the rules were written in, except here obviously because that wouldn't help your position.No, GROUPS (Remember the GROUP'S CHANCE OF SUCCESS), within the TRAVEL RULES, don't notice hidden threats IN ADVANCE. Very different. But for that, you need a game where the characters' actions are taken into account
The rule linking these rules is the core task resolution mechanic, as we've stated: "The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure. When the outcome is uncertain, the dice determine the results." Then we have the rules for passive checks: " A passive check is a special kind of ability check that doesn't involve any die rolls." In this case, because the rules set forth that the character cannot notice hidden threats while engaged in certain tasks, specifically noting that PP does not apply, there is no uncertainty as to the outcome and there is no passive check. The character simply fails.Yes, they work seamlessly as written, with the travel rules REFERENCING but not replacing in particular the rules on surprise. But because you confuse everything in a loop that is too simple, that makes it hard for you to perceive the difference. There are rules for travel and noticing threats in advance, and there are rules for combat and surprise. And although they indeed work together seamlessly, it's not in the way you claim, since you are unable to provide any rule making the link.
Also, since you brought it up, what makes more sense? Making a game meant for ages 12 and up more complex as you suggest or less complex? Simpler seems like the logical choice here to me. Why you'd choose to make it more complicated and Perception strong in the doing is unclear in my view.
Here we go again with "natural language for me but not for thee." Do we really need to have a discussion about what the word "can" as in "can summarize the adventurers' movement" means? That does not suggest any kind of default in my view. The section says sometimes you can summarize and sometimes it's important to be more detailed about it.No, actually, it's the other way around. The section begins with summarising as the default way of doing it. It just says that "sometimes it's important, though, to know how long it takes to get from one spot to another, whether the answer is in days, hours, or minutes."
The funny thing is that because the only line that you think is supporting your claim (it does not) is in the travel rules, in leads you to the absurdity of forcing characters to be travelling all the time so that you can inflict the penalty you think the game needs on your players. But it's not the way the system works, and it's not necessary anyway.