Sure. And if their judgment is deemed incorrect, it will be overturned on appeal. If the matter is urgent, appeal will be expedited. That's how the system works. You can certainly argue that we need more courts to handle the current workload, but let's directly address that issue rather than curtailing the injunction power to reduce the work.
Bear in mind that this was a case where the multiple courts who considered the issue were unanimous in their opinion that the President was very likely to lose on the merits. Exactly the kind of case where there should be an injunction.
These weren't being used in that manner though - Trump was winning on appeal, then a second court would issue the same injunction, forcing him to go through the same thing again. This ruling was needed to stop the courts from abusing their power.
Bear in mind that this was a case where the multiple courts who considered the issue were unanimous in their opinion that the President was very likely to lose on the merits. Exactly the kind of case where there should be an injunction.