Hiya!
A couple people have mentioned the "What if the PC fails?".
The interesting part you’ve not addressed is, what was the possible consequence of failure in the investigation?
It is usually obvious. In the secret door example I used, if the PC hadn't slowed down, their Passive Perception would have been too low. They just walk right on by.
If the Passive had been enough, but then their roll was too low, they wouldn't have found the secret door. I could have described any sort of thing to fill the narrative. Three dead rats arranged in the form of a triangle in front of it, the slight smell of rot being stronger here, or even just 'you find an old rusty dagger with the tip broken off'. Anything to indicate that SOMETHING caught the PC attention (...dead rats arranged as indicator with tip pointing to secret door... rot from behind the secret door wafting into the corridor... rusty dagger with no tip that someone tried to use to pry open the secret door and failed...with the tip maybe still being jammed into the stone wall/door, etc).
Same with Investigation. If they succeed, great. If they fail...they fail. It's NOT my job to make sure the PC's "can advance". Quite the opposite. My job is to present things to try and oppose/stop/hinder the PC's (all within the believability of the campaign setting and situation, obviously). If the Players find a secret door...but don't find the means to open it...that's on them. THEY are the ones that have to come up with some work-around. In the case of the secret door... bash it down, like any other door. Or maybe cast a
Knock spell? There are SOOOO many ways for a group of PC's to still "advance/overcome" something that blocks their progression it boggles the mind!
So, in a nutshell... if the PC's fail some check and the story/progress/advancement is stopped... Not. My. Problem.

I'm the DM, not their mommy. If they fail to figure out how to open a secret door and immediately cross their arms in a huff and say "No Fair! Now we can't go through it!"...well, all I can say is "You suck as a player. Go back to Candyland or Shoots n' Ladders".
PS: I do think that some of 5e Skills are.... superfluous. In fact, the whole Skill system could have been done differently. But hey, it works, even if it's not very "accurate" or "intuitive" in many cases. When it gets down to brass tacks, the entire point of a Skill is to have the Player roll some dice and add some numbers in order to instill a sense of excitement.
^_^
Paul L. Ming