I think a good way to view it may be like this.
As DM, I prep problems, not solutions. This is old advice for challenges and encounters, but it also applies to the plot of a game. I come up with this villain, they are going to do this thing, they have a plan to do it. There is direct given solution to the problem, the problem has to be solved by the players and the methods that they choose. So long as I understand the problem completely, the players can take any path they want, within certain bounds of course. There are rails, but the rails are far, far away; the rails are "This game takes place in this city, and these are the leads you guys have discovered, what do you want to do with these leads?"
This is why I like good setting books too, because a good setting book not only gives me problems without solutions to use for my plots, but also gives me tools to be able to deal with anything the player's do. A good setting book will tell me about the people here, what kinds of likely important places or NPCs there are, what their problems are, and ways to make them interesting.
Most adventures, I feel, do not do this. The published ones, I mean. They give you a problem, but then they also give you actual solutions that have to be used. Having to adhere to these solutions is very difficult for many tables, because the direction a table takes could make getting that solution hard, impossible, or requires silly things like in Dragon Heist to keep the problem from being resolved to soon. This is a textbook mistake in any story: presenting solutions early on that likely should cut the story to a 5th of its length. And likewise, this is something that many amateur writers often do, which comprises the bulk of DMs. Amateur here isn't meant to be an insult.
Likewise, sometimes problems are designed in adventures that don't have obvious solutions, but also don't really leave room for any good solutions. The mechanical dragon unleashed on Ten Towns is a good example of this, from Rime of the Frostmaiden. They gave the problem too much detail, and each detail made it essentially more and more impossible to fix the problem. Likewise, the player's don't have adequate resources yet to deal with said issue, and so, the problem ends up souring a good bit of the campaign.
Making problems without solutions takes some finesse, but WotC are slowly figuring it out. Sometimes they take steps back, sometimes forward. Overall, in terms of home games, this is advice that I think if published would do nothing but improve pretty much every table that took this advice to heart. YMMV.