More 'time saving' measurements, because apparently that's more important than having a fair and/or humane trial
You know how all of HN was in an uproar when the ex-Nicola CEO called HTML a "supercomputer"? Lawyers feel the same way when non-lawyers mislabel things and then get outraged because they think something is one thing when it's actually something entirely different.
This is not a trial...it's a hearing. It is not a legal proceeding on the merits, so it will not result in any factual determinations of guilt, what happened, etc. It's simply a hearing to see if there is sufficient evidence of a criminal case so as to allow for extradition under the UK's treaty with the US.
That is why the defense is generally not allowed to cross-examine the witnesses: it's besides the point for this proceeding. To the extent the defense is even allowed to present witnesses, it's not to contest guilt but to argue against the legality of extradition, such as by showing how conditions might be "inhumane" in US prisons, or how Assange's mental health would not allow for extradition under UK law, etc.
Again: guilt or innocence is irrelevant to this proceeding.
EDIT: link for the curious describing how extradition works in the UK. https://www.gov.uk/guidance/extradition-processes-and-review
"The judge must be satisfied that the conduct amounts to an extradition offence (dual criminality), none of the bars to extradition apply, where applicable, there is prima facie evidence of guilt (in accusation cases), and whether extradition would breach the person’s human rights."
(Note: "prima facie evidence" means that there is at least one piece of evidence supporting every element of at least one of the criminal charges against the defendant. It doesn't matter if that evidence could be rebutted in a trial; only that such evidence exists and is part of the investigative record.)