And what is common to all of these, that there is an objective correct answer. That to me makes it "real solving."
Yes, those 3 x parlor games have
pre-authored solves + either the drawing + the pantomiming + the deft wordplay that are the equivalent of the GMs prep of
initial situation + clues & obstacles & exposition dumps + pre-authored solve in prepped Trad mysteries. That much is kindred.
But that isn't remotely the whole story, which is why I was pointing at
the significant divergence between the two being contained vs labyrinthine. This is extremely relevant for
the challenge-based priorities that matter to the question of "did the integrity of the solve maintain with the players performing the solve sans-GM Force...or did the GM prod/breadcrumb/corral them to the solve in part or in whole...or did the solve not emerge at all because the GM or players (or both) failed at their respective role (devising + articulating for GMs and investigating + solving for players)."
Key here is, in contrast with contained, labyrinthine comes with severe signal dampening noise + breadth and scope (either artificially/incidentally because players start chasing the wrong inference/information set or actually because the mystery is convoluted and vast). When playing a Sherlock Holmes boardgame mystery, there is no accumulating fiction and free roleplay and backstory and "living breathing world" to distract (or inform) the mystery nor is there a GM to damage the integrity of the effort to solve. There is no challenge-based priority, solve-integrity harm to the "legitimacy of the solve" via tried & true (and well-endorsed everywhere...certainly here is no exception) Trad techniques of any of (i) ensuring clues (particularly "essential" ones) find their way into play even if players' investigation efforts would miss them, (ii) GM-rerouting players on Wild Goose Chases or lost in erroneous inference chains via strategic NPC exposition dumps or site-based info dumps (breadcrumbs), or (iii) action resolution manipulation.
Why do GMs in Trad mysteries do this (at scale)? "Because labyrinthine." Because either the core build of the mystery has failed (typically due to convoluted fiction and attendant convoluted inference chains or overwrought breadth/scope that engineers in too much bandwidth-stealing noise into individual and collective player mental space) or the play has failed (perhaps both). Or it could be that the GM basically mainlined Ouija play straight into the mystery architecture. On the surface it looks like the players are doing the investigatory work, but the GM is controlling the planchette which means the investigation strategy > clue-finding > inference chain > legitimate solve = a complete veneer. And once the GM has interfered with the integrity of the investigation strategy, the clue-finding, the inference-chain....any of it...to any degree...well, the legitimacy of the solve in terms of challenge authenticity is kaput. The integrity of any related challenge-based priorities becomes zero and the force of “but the solve was written down beforehand(!)” does the same work; zero.
The Sherlock Holmes boardgame mysteries fail at an alarming rate; probably 60+ %. This is “expert” boardgame mystery writing and unburdened by TTRPG’s obscurant dynamics mentioned above (it is just straight solving of a singular mystery with no other priority nor TTRPG-specific phenomena, like "living & breathing world" content, vying for table time and precious mental bandwidth). There is no way Trad mysteries (which necessarily folds in the large % of those mysteries that feature the challenge-integrity destroying techniques above which are tantamount to “the GM playing the game for the players”) do better or even near that number. My guess is, folding in that GM Force intervention above as a failure-state, Trad mysteries flop at an 80 % clip or worse when it comes to solve-integrity or successful solves. I'll give you a very charitable 20 %. 1 in 5 feature (a) well-built and well-GMed mysteries + (b)no GM Force to corral and guide the investigation strategy/clue gains/inference chain/solve + (c) players coming up with and executing the correct, pre-authored solve. I suspect the number is lower (I've only heard about these unicorns in the wild...I've never seen one...but boy have I heard about and seen the opposite!), but I'll give you 1 in 5.
This is the point and the reason to contrast Pictionary/Charades/Taboo with Trad TTRPG mysteries. Same goes for Pawn Stance dungeoncrawling where it is basically a sequence of isolated (contained) puzzles/obstacles and a strategic throughline of logistics and resource management. It is where they diverge that is the consequential piece, not the overlap on the Venn diagram...and what that divergence yields in terms of solve legitimacy (which only matters if your play champions these related challenge-based priorities as the hill to die on).