Again, not sure what part of "official" you missed, but it's all professional, written by professionals, formatted professionally, etc.. I am NOT talking about general DMs Guild. I am talking about WOTCs official Adventures League DDAL adventures which are published on DMs Guild.
Maybe click on ANY link in the link above that you quoted? You will see the author is not "some dude" but "Wizards of the Coast".
Again, I think they've done a deep disservice not advertising these to the general public despite making them available for sale to the public. Only AL DMs seem to know about these. Even though they're exactly what non AL DMs have been asking for, for a while.
Here, check this out and tell me this is amateur hour stuff. LINK
Yeah, more seriously, WotC does produce hundreds of pages of professional Adventure content per year.