Why did the Supreme Court dismiss California v. Texas without deciding whether the individual mandate was constitutional?

In the 2021 case California v. Texas, the Supreme Court did not rule on the constitutionality of the individual mandate or its severability from the Affordable Care Act. Instead, in a 7–2 decision, the Court dismissed the case because the plaintiffs lacked standing to sue.1

Standing is a fundamental legal requirement ensuring that a party bringing a lawsuit has a personal stake in the outcome and that the dispute is presented in an adversary context suitable for judicial resolution. The Court determined that the challengers in this case failed to demonstrate that they had suffered a concrete injury traceable to the individual mandate, which had been rendered unenforceable as a tax penalty by previous legislation. By failing to establish this necessary legal standing, the plaintiffs could not invoke the authority of the federal courts to adjudicate their grievances.213