I'll see this and challenge a little. And it may be you are perfectly aware of all this, and are just working within the confines of existing 5e because it's the big gorilla and such - in which case just laugh at my soapbox?
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In my humble opinion, the way D&D5e uses Perception and traps sucks – it boils down to the de facto "gotta have someone high in passive Perception" has become de rigueur for play – because it is has no context to the type of trap / game use of the trap.
For example, big obstacle obvious puzzle-traps should not involve Perception at all. The GM just needs to say what they need to say.
But there are less obvious situations where this is equally true, for example if it's a trap that might be detected a certain way but is otherwise completely undetectable otherwise – and there is a clear game precedent in 5e monsters with False Appearance traits (at least the original pre-MMotM version) requiring things like detect thoughts or interaction to detect – the GM move should be to foreshadow, not fall back on Perception. Example from game: I put a warding glyph that was under a rug. The spell describes Investigation detecting it, and that felt stupid. Instead my narrative foreshadowed that these glyphs glowed in pitch darkness, so there was a gameplay element of "do we risk snuffing our torches/extinguishing our magical light when searching for glyphs?"
I have a bone to pick with the Perception skill more broadly, it's true, I am biased. However, I'm limiting my disagreement here specifically in the way in which Perception interacts with traps as a "one size fits all super-duper detector."
The counter-argument I typically hear at this point is: "Well, Quickleaf, you don't say there's a trap if their passive Perception is high enough, you describe context clues." To which I have 3 responses:
1. Actually, the adventures and DMG itself give advice & examples that aer contrary to this. So it may be best practice, but it's not what the 5e game books currently demonstrate.
2. At that point, what purpose did the roll / maths check serve? Couldn't you have delivered the context clues from the get-go? Did you really gain that much from the Perception ordeal?
3. Without well-written clues, it's not obvious to all GMs how to deliver good context clues. It's a skill GMs develop through lots and lots of experience – old hands like me don't need to be told this because we are already doing it and have been for a while.
There are certain traps – typically the "gotcha" that is prevalent – where the whole Perception ordeal becomes necessary for fair play. But that's far from the only way to skin the cat...
For example, I house ruled 5e Perception – it's now explicitly Danger Awareness and functions more like a saving throw when the PCs are ambushed or trigger a trap. Are your surprised? Perception roll vs. the enemy's Stealth. Are you caught off guard by the trap? Perception roll vs. its DC, and if you succeed you can take a quick reaction (like diving 5 feet, dropping prone, dropping an item, shouting, using a reaction ability, raising a backpack in front of your face, etc) in response to the GM's description of the trigger going off. I've only tested a little, and struggling to get players to remember the house rule, but it has done wonders for cutting down on the lazy: "I search the room for stuff like traps or anything interesting. My Perception check is 17." No, no, no. Instead, if they want to learn about the room they've got to use their heads and their mouth-boxes and start interacting with stuff. Unless they have X-Ray Vision, they do not get x-ray vision.
To which iserith arrives and says: "That's not the 5e rule. The GM calls for the check!"
And my response will continue to be: "Yeah man tell me about. Players with habits are so hard to break. But I'm optimistic that my Perception house rule will help with that...or flat out deter habituated lazy players."
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