It seems that the version you saw is different. It's not about a group of teenagers. The story focuses only on a teenager, who commits a crime and we see the repercussions it has, both in his school environment and in his family environment.
I don't understand what you say about the sequence shot, it is the resource used by the director to shoot each episode, something the director already did with one of his previous productions Boiling Point, a film that had a sequel in miniseries format.
Can you tell me a couple of films or series that have the depth that you like? Because especially the stories that go very deep into their characters, they have a slow pace and I'm sure there are deep productions that are much slower than this one. Adolescence I think has a pace and tension that is in line with what it tells.
Also could you tell me what are the plot holes you noticed?