I live on the outskirts of Wrexham so I think I’m fairly well positioned to say that the town has not been transformed and is still just as much of a shithole as it was before, albeit one with a better performing football club.
One thing it has done is conjured a (small) tourism industry in the town pretty much out of thin air. You can't knock that, even if it's not exactly transformational.
A lot of towns which are on the permanent downward slide could do with even that small shot in the arm.
Although to be honest it's all a bit of a red herring, as Wrexham's economy was already doing better than many of its peers. As "North Wales industrial towns" go, Wrexham was doing alright really. Having a shit football club is hardly the worst fate to befall a town.