Feels like (IME) there's a rather high incidence of discontent over decisions "from above" among the shows listed: The OA being cancelled, 13 Reasons having three seasons too many, speculation(?) that Dark's wonky pacing at the end was due to being approved for too limiting a number of episodes...
Game of Thrones had a horrible final season. The first six seasons were maybe the best in all of television.
It's rare for a TV series to be excellent and stay excellent it's entire life.
This doesn't really seem unique to Netflix.
There's a ton of movies, shows, books - where the first installment is outstanding and the rest are trash.
My favorite example as a kid was Maze Runner. The first book has terrible prose - but is actually pretty well paced and a good story. The second two are utter garbage (fun fact: the editor quit after the first book AND the publisher dropped the author when the first one was the next best selling sci Fi / fantasy since Harry Potter... That's how bad the sequels were).
(Can't edit) Ah, how did I forget, in this context, about the suicide being censored out of the first season of 13 Reasons Why, years after its release?[1]
That was along with the addition of 1) a disclaimer in the form of the actors talking directly to the viewer before the first episode and 2) an intertitle after every episode reminding of it, again with narration from the actors. 3) Trigger warnings before episodes were also added, but to no surprise at this point. What I certainly haven't seen before is such mutilation of a work as accompanying it with material so expressly immersion-breaking!
A song in the soundtrack was also replaced for reasons unknown, but I suppose that falls more into the general topic of silent alterations to published media that online consumption facilitates, an entire discussion to be had on its own.
