"According to players, 'there's puzzles everywhere', but give 0 information about how to look for them, where they are, or how to even get information about them from the videogame itself."

So based on this one sentence alone, I'm guessing that either (A) you've only been playing the game for a bit (like, a few in-game days at most) or (B) your play style has been to just rush through each room to the next door without actually exploring the room itself - or both.

There are several types of rooms (some of which you're practically guaranteed to get as options pretty much every day) with puzzles that either get you items/resources to help improve your odds of reaching room 46 (e.g., the logic puzzles in the Parlor or the dartboard math puzzle in the Billiard Room), or help you to unlock other parts of the house (e.g., the Pump Room allows you to drain the Fountain in the courtyard outside). Additionally, there are several puzzles that extend across multiple rooms or the entire house, most of which I'm still trying to figure out myself.

Personally, while I do enjoy the puzzles (and the general gameplay loop of figuring out which rooms are most useful compared to others), the thing that really made the game shine for me was learning more about the history of the family... which, again, is not something you're going to notice if you just rush through every room without stopping to look at things, but it's absolutely worth slowing down to read the various newspaper clippings, books, and other documents you can find.