It's not just Sheffield
Michael Ellis raises a good point regarding Sheffield becoming a pub free zone, but it's not just Sheffield, go anywhere in the surrounding area and you'll find that it is the same story.
The answer is quite simple; drinks in public houses etc have become far too expensive leading to more and more people buying their drink from supermarkets at a far cheaper price.
Why should breweries support pubs when they can sell alcohol in cans, in supermarkets, with nil overheads.
£4.50 a pint of lager and £4.50 for a pint of lager shandy made sure that I never visited one particular pub again.