The reduction in the value of the £ has been tried before, many times, and it is a failed policy.
We have to import many, many raw materials (to say nothing of fuel which is priced in dollars.) These increasing in cost means that output prices increase in cost very soon after, and bang goes your advantage.
Another issue is that UK assets - such as houses - become cheaper for foreign buyers. So speculators (like the Chinese) buy up more houses and flats to rent out. And people wonder why house prices and rents keep soaring.
This budget is a huge, reckless gamble. That it is perpetrated by an alleged 'Conservative' government - who have always claimed to be the party of fiscal responsibility - is fucking mind-blowing.
It isn't quite on the scale of Adolf wanting to destroy Germany's infrastructure when he realised defeat was inevitable, but it is in the same ballpark.
If the UK public has any sense, the Tories will be smashed at the next GE.