Yes, I see where you’re coming from. I think it’s possible that your lack of interest or experience is making you… less sensitive, perhaps, to the subtleties, which can loom quite large to a person who’s deeply committed to this goal.
For instance, the “invisible rules” (let’s call them GM techniques, perhaps?) have to interface with the “visible rules” in a productive way. This is where PbtA design often falters.
As an example, one of the things that is important for engaging player cleverness in OSR play is the impartial role of the “referee”. That impartiality, to a large extent, drives the risk/reward aspect of being “clever”. So the mechanics are very often/usually formulated in such a way as to allow and support that referee impartiality. Things like reaction rolls, morale checks, explicit rules for XP rewards (e.g. 1 GP = 1 XP), and strict rules around timekeeping and encounter checks all allow the referee to keep their “hands off” the outcomes.
PbtA rules, though, instead, give all the players decision points and impact on everything that happens. (I don’t know if you’ve ever seen OSR fans look at something like Apocalypse World, but sometimes the first reaction is: “What’s with all these lists? I don’t want to choose - this game would be better if there were numbers beside each list, and we could just roll a die.” You can easily see how this is missing the point of those rules - which is, precisely, to create space for agency and expression.)
So, in old school D&D, whether a monster from the next room comes investigating is based on a series of sequential procedures - did the players gauge risk and reward appropriately? For example, did they carry so much armour and treasure that their movement rate was low enough that they had to roll for an encounter here? In theory, you don’t even need the referee to determine this. It’s based on a series of decisions on the part of the players, and the known risks associated with them.
In a typical PbtA game, though, instead, the players make their moves, and if they roll poorly, the choice is placed straight in the GM’s lap: “Ok, your turn to talk. What do you think is interesting here? Want to have the monster attack?” The GM could, in theory, ignore that, and rig up some relatively impartial method to determine whether the monster attacks, but, even then, the reason she’s making that call is because the rules say this is what she does when the players roll a 6-, not because of a string of decisions the players made to get here in the first place.
This may sound like a subtle distinction, but it makes a big difference.
Another example is: where does the content of play come from? In an OSR style of play, there are prewritten modules, with their own content and rules. Many people look at something like B/X D&D and they think “well, these rules don’t do much…”, missing that, in fact, the rules and procedures for play are often in the modules used, moreso than the basic ruleset.
This also enables this approach to play.
As I’ve said before, none of this is impossible in a PbtA design (a definition which is almost impossibly broad!), but many of the typical features we associate with PbtA design do not support it well. A PbtA game which did support it well might no longer look much like a PbtA game at all.
It calls itself PbtA but it has no picklists, for example. But then, I don’t really regard picklists as “core PbtA design” either, so… eh?