The reason the PASPA was unconstitutional wasn't because the federal government can't regulate sportsbetting. It was due to the specifics of how the PASPA implemented the ban. In particular the authors of the PASPA wanted to "grandfather in" certain states so rather than making sportsbetting illegal nationwide/federally they made it illegal for state governments to pass new laws legalizing sportsbetting in their states (which meant that states which had legalized sportsbetting already could continue to allow it).
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.