I’ve lived in Sheffield for about 6 years now, plus a year back in 1996. I’ve always wondered why Leeds which is supposedly much smaller seemed more vibrant. The sidebar in the BBC article says it all: Sheffield is poorer, less educated, and shrinking working age population.
Personally, I love Sheffield, although it would be nice to have a Manchester-class airport with (almost) direct flights to Indonesia! Maybe some airline will start flying from Robin Hood.