why are the official chapters usually at the far end of the list of chapters? is it coz they are later than the others? some readers didn't even know they exist until someone tells them
I can think of 2 reasons why,
1. when you click "Start Reading" it starts you right from the bottom of the list so if the officials are at the bottom you read right from them and not the unofficial chapters.
2. the fan-tl is almost always far ahead of the officials so they tend to stick closer to the top as to avoid mixing with the official chapters.
also most uploaders (not all but most) label their chapters with "official" on them, so you're still able to tell right from the "Latest:" section under where it says status, author, genres & alt name, if an official chapters been uploaded since you'll still be able to see it at the top of the page even if it's not at the top of the chapter list. for me personally I always scroll the full list regardless of what kind of update the stories gotten but that's just me.
Uploaders have control over where their chapters appear on the list. That said, I honestly think it's much better for the official uploads to stay at the bottom when there's both an unofficial version and official version being uploaded at the same time since it separates them from each other.
If a series has 40+ chapters, moving them isn't as simple as dragging them around. You have to go through the same editing process as if you were uploading the chapter in the first place, and you'd have to repeat that for every single chapter.
To put it simply, from my experience, unofficial uploaders (usually the AI slop groups, if I'm being honest, since regular scanlation groups are a lot more considerate) just upload their chapters using the default setting, which places them at the top of the list.
Now imagine the official uploader also used that default setting. Their chapters would also be published at the top. I can almost guarantee the unofficial uploaders would keep using the default setting too, so official and unofficial chapters would end up mixed together. You'd have duplicate chapters from both versions sitting right next to each other throughout the top of the chapter list, making it really frustrating, if not impossible, to read consistently from either the official release or the unofficial one.
Keeping the official chapters at the bottom separates the two versions into their own sections. In my opinion, that makes the chapter list much cleaner and a lot easier to read.
I saw this clarification from ZIG (author) on the topic of incest among the brothers that's always been misunderstood. I hope this spreads. https://www.mangago.me/home/mangatopic/22846836/