I think that the idea that there are prescribed story/plots is the biggest misconception of published adventures. If you believe that to be true, it sort of tells me your approach is rather old school with a west march style. Thats not bad, but it also doesnt mean adventures not written in such a style are bad either.
To frame it in a way that hopefully makes sense, is to view a published adventures as kits instead of paint by number instructions. For example, the adventure will have a villain, lets call them BBEG for ease of use. The adventure usually takes place in a region, a town, etc.. The adventure should color the setting with interesting people, places, and events. BBEG is engaged in some conspiracy and/or plot the PCs have to unravel, discover, and confront. The GM is armed with the info to allow the players to engage as they see fit. More importantly, they understand the BBEG's goal, and can react and become proactive as the adventure progresses.
The only thing different than what the OP describes is there is a BBEG with a connection to the region, the people, and events. Just lists of encounters and local color, but with link between them and how the GM can make sense of that for their players. The absense of this makes the idea more of a setting book than an adventure book.
In summary;
- Detailed players guide that gives players mechanical assistance with chargen that will align with the material.
- Organized tables of info for the GM to run efficently.
- Detailed people, places, and things with solid links to overall adventure.
- An engaging conspirtal plot that is flexible to player agency.