What York does is simply provide the dates on which Team Mueller interrogated most of the best known supposed "colluders" or Russian agents. It turns out that most of them were interrogated quite early on. After quickly disposing of "collusion," presumably they had plenty of time for obstruction.
The Carter Page example is telling:
For example, a key figure in the conspiracy allegation, Carter Page, was not on the White House radar screen. But in a new podcast interview, Page, too, said the special counsel's office was finished with him by the end of 2017.
Page did five interviews with the FBI in March 2017, before Mueller was appointed. Page said he had just one appearance with Mueller's prosecutors, and that was in the grand jury on Nov. 17, 2017. Asked if that was the last he heard from the special counsel's office, Page said, "Yeah, essentially."
Five FBI interviews--before Mueller was even appointed! And only one later, before the GJ. I'm guessing the GJ appearance--six months later!--was an attempt to pin a perjury rap on Page. Pathetic, but the point is, with Page--the supposed courier between the Trump campaign and Putin--basically eliminated before Mueller got his Hillary lawyer team assembled, who thinks he really believed collusion was a thing? And, come to mention it, who thinks Rod Rosenstein believed that?
Now, to be fair, Mueller did some additional investigation of his own on Page but, with only one exception, that was all completed by July, 2017:
One of the officials at the Moscow school at which Page gave a speech was interviewed by Mueller on July 28, 2017. Another such official talked on June 9, 2017. Sam Clovis, a Trump campaign official who Page told about the trip, was interviewed on Oct. 3, 2017. Corey Lewandowski, then the campaign manager who had some dealings with Page, talked on June 19, 2017.
The same could be said about George Papadopoulos, who pleaded guilty in October, 2017, on trumped up (!) false statement charges that were unrelated to anything Russian. All that investigation had long since been completed.
Read the whole article--York cites plenty more examples, but it all pretty much follows the same pattern, except ...
York makes an interesting point near the end:
In late 2018, the Mueller team appears to have embarked on a collusion wild goose chase, looking for evidence of a Trump-Russia conspiracy among Roger Stone and Jerome Corsi. Mueller's prosecutors interviewed Corsi over and over — on Sept. 6, 2018; Sept. 17, 2018; Sept. 21, 2018; Oct. 31, 2018; Nov. 1, 2018; and Nov. 2, 2018. Corsi was never charged with any wrongdoing.
Wait ... late 2018? Wouldn't that be time that Rosenstein and Mueller realized they would be getting Bill Barr as the new Attorney General? And hadn't Barr--six months earlier--written a 19 page memo explaining why Mueller's obstruction theory was illegitimate and irresponsible? So maybe they figured they better come up with another "collusion" theory just to keep the Russia Hoax going longer. If that was the idea, Barr wasn't fooled.