Black Mirror was never made by the BBC, and all episodes of Sherlock were made by the BBC not by Netflix, so neither of your examples make any sense and don't allow you to compare what you are saying they would.
Abstract is triple-A. A Chef's Table is triple-A. Stranger Things is triple-A.
We all have a sort of cynical habit of presuming that things once were good, and now they aren't. But Netflix has always been a mix of good and bad original content, especially when viewed from the subjective eye that what some of us think is great others think is terrible. They're trying to serve all markets.
I've started watching The OA and it's the first series that I've noticed each episode is a different length. Some episodes are around 30 minutes, others are more than 60.
The only thing I can think of that's really different is opening/closing credits, but given that I pretty much never binge-watch anything (and apparently most of my friends on Facebook don't either), those serve a useful purpose for me, in that they help set the mood and make it so I don't have to wait a few weeks to figure out who played that street vendor that showed up one time in chapter^Wepisode 3.
That and the gentle recaps they often have built in. In the UK when we air US TV shows they often seem really weird because when there would be an advert break in the US parts of the story and sometimes even lines are repeated by the actors to help you get back into it. Sometimes you get a cliffhanger line, a sort of a second's pause, and then the cliffhanger line repeated in a different tone! Where we don't have advert breaks this comes across as bizarre until you think the US would put an advert there, and you get the same kind of thing but across episodes on Netflix.
(Mind you I have a low tolerance for TV drama; the last two things I really enjoyed were Foyle's War and Endeavour)