After watching the replay a number of times, it becomes clear that Vettel rejoined the track and was in control of the car. His trajectory was not on the racing line, but he steered right to block Hamilton. Now, I don't blame him, this is what every racing driver in his position would do. But apparently, that did weigh in to the stewards' decision to penalize him.
https://www.autosport.com/f1/news/143996/vettel-steering-inputs-key-to-fia-penalty-decision
I don't agree with you here. First of all, Hamilton didn't call for a penalty, he just said that what Vettel did was dangerous. Hypocrisy? I dunno... But I do know that Ferrari had the fastest car this weekend.
Maybe not six tenths, but you could see Vettel pulling away from Hamilton on the straight even when the latter had the DRS open. Hamilton would creep back into DRS range around the twisty parts, but could not get close on the straights.
Mercedes as a team and operation are the current gold standard in F1, no doubt. But last year Ferrari probably had the quickest car over the entire season, they just failed to capitalize on it. Even this year, they have been faster on some tracks, they just haven't been able to put it together. They locked out the front row in Bahrain, and Leclerc was comfortably leading the race until his engine lost power. Leclerc probably would have made pole in Baku as well, had it not been for his crash in Q2. This weekend again, their car was the fastest and Vettel should have won this race.