It's helpful to understand the District Court's decision to dismiss and the standard employed. It was on a motion to dismiss pursuant to Rule 12(b)(6) of the Federal Rules of Civil Procedure for failure to state an action for which the court can grant relief.
Under this standard, the Plaintiffs' complaint must be facially deficient. The court is required to assume for purposes of the motion that all of the facts asserted by the Plaintiffs' are true, but that even assuming all facts alleged are true the Plaintiffs can't win as a matter of law. As you can see this is most generous standard Team Trump can ask for. At this level they need not provide any evidence at all, the court just assumes for the sake of argument that they will provide evidence that will prove every allegation of fact they make.
Under this standard the court found Team Trump lost because:
Plaintiffs lack standing, and so they lose. Standing is a fundamental jurisdictional question. Without it the court has no jurisdiction to go any further or even to allow discovery.
Even assuming Plaintiffs have standing, they do not adequately allege an equal protection clause violation, and so Plaintiffs lose. Thus, the court's assume Team Trump failed to even allege facts, that if assumed true, would rise to violating the equal protection clause of the Constitution.
Even assuming Plaintiff adequately allege an equal protection clause violation, the court might could grant a remedy ordering counting the handful of Plaintiffs’ votes not cured to be counted, but the court cannot grant a remedy disenfranchising millions of other voters, and so Plaintiffs lose.
As you can see, the court gave every deference to Team Trump, even assuming legal arguments it already reached were wrong and finding that Team Trump still loses.