A low pound is good for British exports and tourism to the UK, but harms British buying power of imported goods. If it's good or bad depends on your viewpoint, I guess.
Tourism perhaps, not that good for exports when we have to import all the stuff we use to make the exports and/or most of your exports are service based.
This might help you see some problems.
At some point the exchange rate falls and suddenly no one is happy with it either. Recent examples are China, GB, Brazil, Venezuela.
The truth is - as with your comment - a surging/falling exchange rate is neither good nor bad. It has positive and negative effects and things will balance out.
Or to say it differently:
An exchange rate is never low, nor is it high, it is precisely where it should be. - Gandalf the Grey
In this case the other countries are dumping GBP because they think the UK economy will become weaker. That would be like a Sales because your product is flopping.
Same effect, difference cause. One is voluntary on the country/company term, the second is forced by the other actors of the market. The fall of the GBP is significant. The rest of the World is shorting the UK right now and that in itself can be what pushes the UK economy in danger zone.
"That pattern is however a rather unbalanced one, the only sector of the economy that continued to grow was services up by 0.8%; agriculture, manufacturing production and construction all shrank."
What exactly about Brexit spurred this leap in the growth of yoga studios, burger chains, and Star Trek box office returns (A drop in the GBP, as it turns out, for the latter)? Because it seems like losses in everything else is pretty much what economists expected. Manufacturing declined despite a drop in the GBP.
And all the news about how the pound has tanked against foreign currencies, which will eventually push up the cost of almost everything. The days in which physical UK exports were made out of commodities that aren't themselves imported are long gone.
Non-physical exports might fare better, but the news about banking and financials has been about how they're doing due diligence on moving to elsewhere in Europe, so that's bad news.
Sure, I've heard some positive news too, but I've heard a lot of negative news. How come you haven't?