In many published adventures there really isn't much if any in-fiction justification for the wandering monsters they expect a DM to use, which is why I tend to largely ditch wandering monsters unless there is a good justification for their presence.
For example, if the adventure is set in an Orcish stronghold with a population of many dozens then occasionally bumping into a few Orcs makes perfect sense. Or if somewhere in the dungeon there's a spawner that every so often churns out three ghouls at a time, then meeting groups of ghouls makes perfect sense until-unless the spawner is shut down, after which there'll still be some ghouls wandering around but the frequency of meeting them should steadily become lower.
But if the same module lists, say, giant ants as a wandering monster in those locations, I won't use them; the Orcs would long since have wiped the ants out at source (or harnessed them as a food supply, whatever) and the ghouls would likely take care of any ants they met long before they got to the PCs (though just for kicks and variety I might toss in a giant-ant-ghoul or two).
See, but then this is you deciding how the events of play are allowed to go. Instead, why not find a reason for there to be ants in the orc stronghold? This is related to the idea of the GM discovering during play. You roll ants on the random encounter table... now find a way to explain their presence here. Instead of discarding the random element and simply taking the reins yourself.
There has been some interesting things, and I appreciate when people are willing to answer dumb questions. I don't think one set of rules is superior to another for everyone, people like what they like.
I don't think there are stupid questions about this stuff. It's not always easy to understand or explain in a forum, where multiple people are discussing the same topic. I think a lot of good questions were asked.
What frustrated me was the way in which answers given were, at times, twisted to return to the same conclusion.
"How does this work?"
"It works like X."
"Oh, so it's not even Y."
There was a lot of that. A return to the flawed premise rather than consideration and understanding.
But things like "this wouldn't happen", "you won't get bored because of the rules", "you won't have a problem with a DM wielding ultimate power", etc. sound an awful lot like extolling the virtues of a different game system.
I think that "this wouldn't happen" is pretty true of PbtA type games in regard to the situation from the OP. The GM clearly had a lot of input into how that scenario unfolded, and arranged for the situation to go the way it did. If there had been checks on his ability to do that, then it would have went differently. I don't think this is really all that contentious.
I don't think any game can prevent possible boredom. Nor do I think anyone said that. That a game can be designed to focus on more momentous events than another game is just a fact. It can even happen in D&D. For example, I do not roleplay shopping. I just don't do it. You want something, you go to the shop, you pay for it, you have it, and then we move on. If you want to haggle over price or something, we make one roll and then we move on. I'm not interested in pretending to shop, and so I skip it. A lot of people will say "oh but you're missing the possibility of something interesting come up" and so on. I'll take my chances.
As for the DM wielding ultimate power, some games that's just not the case. While this may be someone's preference for their games, it is also just a fact. And I think we can see how that may have influenced the outcome of the OP.
I realize that sometimes it may seem like folks are bashing D&D and claiming that other games are without flaw... I've been guilty of it. But I think in a situation like this thread, we can see the pitfalls of how D&D distributes authority amongst participants, and how games may benefit from alternate structures. It's a perfectly valid point to make.
