You can make these kind of consequentialist arguments anyway. It's worthwhile discussion. But the legal decision itself wasn't made on a consequentialist basis. The court didn't decide PASPA was illegal because it was socially bad and we'd have a better world without it. The proposed "just ban it outright everywhere" can't happen under the current legal regime. It's fine to propose things that can't happen but we should acknowledge this becomes a hypothetical discussion.
It was this "commandeering" of the state legislature's right to legislate that was found unconstitutional, not the federal government's ability to regulate sportsbetting. So if congress wanted they could pass a law that made sportsbetting illegal at the federal level and put a federal agency in charge of enforcing it.
Its similar to the legal weed situation. States can't be forced to enforce federal laws, but the federal government itself can enforce those laws even if the state governments are unwilling.