In the US courts system, juries are used to determine questions of fact, but if the facts are not in question, a judge can apply the law and there's no need for a jury.
Agreeing that there's no question of facts speeds the whole process along quite a bit. There's no need for witness testimony, it can all be managed in hearings and with breifings.
It's possible to avoid a jury trial in a civil case by removing from dispute the issues which would give the other side the right to demand a jury trial.
Each individual legal rule isn’t formulated according to a free-ranging consideration of what’s “beneficial to society.” It would be impossible to administer such a system of rules based on ad hoc policy considerations.
The rule here, the Seventh Amendment, confers a right to a jury trial when one would have been required under English common law at the time the seventh amendment was written. Roughly speaking, in the English system, cases involving monetary damages were handled in courts of law with juries. Cases that involved injunctive relief (orders to do or not do something) were handled in courts of equity with decisions made by judges.
It's only resolved if the court agrees that the amount tendered is the limit of the monetary judgement it would legally be possible for the government to secure at trial, and that such a tender does remove the issue from the case (both of which are disputed points) in which case the damages issues would be resolved and removed from the case, and the rest of the case would go forward, but as a bench trial, not a jury trial.
I'd like to add the perspective here that only the US "makes routine use of jury trials in a wide variety of non-criminal cases" [Wikipedia], so most of the world believes that justice can take place (at least in some circumstances) without a jury
Agreeing that there's no question of facts speeds the whole process along quite a bit. There's no need for witness testimony, it can all be managed in hearings and with breifings.