That power existed before the referendum too. The leave campaign was full of intentionally vague statements that were emotionally charged but lacked any factual substance.
Our “sovereignty” hasn’t changed. The NHS didn’t get any additional funding. Trade deals have gotten worse not better. The whole thing was just smoke and mirrors.
Literally the only thing the referendum was sincere about, was David Cameron’s desire to consolidate votes and reduce the number of his own MPs leaving for other right-wing parties.
He succeeded at that, but its cost the economy literally billions.
It didn’t before. Any individual could appeal to European law via Judicial Review to overturn an act of parliament where it fell into the EU treaty ambit - particularly if they were European.
Now we’re out of the EU that option no longer exists and we can now pass legislation that cannot be stopped by the courts