That's because Sunak isn't a good choice as PM.
It was either you, or the potential deal that was oven ready. I used to think it was the deal that the EU scuppered, but since you bring the phrase up, maybe it was you after all.
However it is good that you realise, not replacing inappropriate laws isn't a good thing, and isn't what Brexit supporters expect from the nation's leader. Still, the opportunity to change them later still exists, which wouldn't be the case had remainers got their way.
Fairly certain it won't take anywhere near that long PP. Can't recall the fellow's name but the media have, on a number of occasions, given this lawyer type a voice who says and had a blueprint for how to get it done much faster; and indicating those who insist otherwise are merely looking to delay and ideally for them, stop the law changes.