Swarmkeeper
Hero
True, to some extent. What I've been describing is the play loop from 5e. The DM describes what's obvious about an environment and then the player decides what their PC wants to do next. It scales just fine. Larger areas might have more stuff to examine or simply take more time to fully search, which could have its own complications (e.g. wandering monster checks).A lot obviously depends on the scale of the area being examined, too.
Sure, just looking into the closet might not reveal anything but a more thorough search of the closet might auto-succeed in finding the secret door. Perhaps the release is not as obvious and so we get to an Int(Investigation) check to figure out how the secret door works.But even if you've got something like a closet, a casual look is pretty likely to fail to notice the hidden release for the secret door in the back (even with someone with good Perception) but a more extensive look for detail might not.
I think the 5e play loop description actually does cover all these kinds of things rather elegantly.Its hard to one-size-fits-all these kinds of things.
Based on some of your other comments, do you perchance mainly play a different edition?