How many DMs other than, from what I can gather, Sunic, run every single monster and NPC in their campaigns as heavily optimized, extraordinarily intelligent, unnaturally paranoid, full casters? Because trying to argue that mundane stealth is worthless because of a combination of spamming CoP and usage of Mindsight, Lifesight, AND Touchsight implies that every adventure in every campaign ran by any DM does this all the time in every encounter. Which, I shouldn't have to point out, is ludicrous beyond belief.
1: COP is an example of Divination, aka the kind of recon that actually accomplishes something other than character death. It is not the beginning and the end of it. So stop mentioning it as if they were.
2: Most enemies do have above average intellects. All of them live in Darwin's Paradise. Just like you do. Which means it isn't "unnaturally paranoid", it's "par for the course".
3: Most monsters can cast spells.
4: Humanoids that aren't full casters, and are NPCs are complete wastes of space, even when selecting the best non full casting classes. Lack of WBL is a bitch like that.
5: Since every example has assumed mid or high levels, on top of all that you have the little fact that you don't fucking survive this long if you don't take precautions.
6: When you get caught, be it by an auto win button, because enemies are better at skills than you, or whatever you're now alone, with an encounter meant for the whole party. Hope you have a new character ready, because this one is fucked.
So let's look at some actual situations from an actual game:
Hm...
Situation 1: PCs pick a fight with a guy, and his very visible guards. They get ambushed because there are more guards hidden. Said guards are auto spotted by Mindsight once they appear. The only reason they weren't exposed on the spot is lack of LoE, aka they were behind a low wall, and therefore couldn't see anything. As soon as they popped up...
Had the party used divinations, it'd have been not too hard to figure out. Had they scouted normally, the scout would have utterly failed to see the hidden ambushers, and would have likely been spotted by the same. Not to mention the very obvious guards would have quickly gotten annoyed if they saw some fool sneaking around.
And any scout that gets busted gets beaten down by 4 chain guards, still has to deal with the ambushers, and also has to deal with the main guy. All at once. I take that back. Saying he's dead in 1 round implies he'd survive the entire thing.
Situation 2: Single enemy is well hidden, and lying in wait. Said enemy is auto spotted by Lifesight, else he'd have not been spotted at all.
Divinations wouldn't have helped too much, though it depends on which.
Scouting would have resulted in the scout being spotted, and not spotting in turn. His first clue something was wrong would be having flying summons, who were formerly invisible appear surrounding him. Oh yeah, and this attack could be Dimensional Anchor, so fuck you Dimension Door, aka the only viable means of escape. The party noticed the problem sooner. The party was also all there.