Chaosmancer
Legend
Well to be fair, this happens IRL and to large extent is the point. Ambush hunters will lie perfectly still for hours until unsuspecting prey strolls right up to them, and I mean right up to them.
BUT that kind of stealth usually involves being motionless in a great deal of cover. As it turns out, moving around the open isn't a great recipe for not getting noticed. Now, D&D isn't even trying to go for realism, obviously, and that's being used as creative license to "simplify" the rules. We're going for the Hollywood version of stealth, fine. FWIW I'm not against simplicity, so I'm all for D&D trying to make this simpl-er.
I just don't think these are good rules. To your point, I can see all sorts of scenarios where these mechanics lead to nonsensical outcomes. That's just me, though.
Yeah, and how many action movies do we have, where some grunt walks down a hallway... then the hero steps out of a dark nook, or flips down from the ceiling, having completely hidden from the grunt?
Technically, the darkness could count as being obscured, and maybe people would say that being in the rafters of a hallway counts as cover, but these could also be argued as not counting as those things, yet in the scene, the character is literally not visible until after the grunt passes.