It looks like this isn't a UK only problem. Even as President Trump proclaims "I am thrilled to report to you tonight that our economy is the best it has ever been" it seems that well known US retail establishment, Macy's, is finding life difficult:
https://www.npr.org/2020/02/05/803016213/macys-closing-125-stores-cutting-2-000-jobs-as-mall-stores-struggle
Perhaps online shopping trends and home deliveries mean that more retail units will be used for more social purposes - coffee shops, restaurants, bars, personal grooming/beauty, medical and other services? Longer opening hours might help but might also mean extra costs for wages, heating, lighting, etc. I've always thought the decline in office space would have more impact on those establishments where office workers went for a lunch time snack, or after work drink or meal with colleagues?