Regent Street, one of London’s premier shopping thoroughfares, is struggling to shake off the lingering effects of Covid-19. Store vacancy levels, at a record 12 per cent, are almost twice what they were at the end of 2019, while rents for the best space on the street have fallen by more than 30 per cent during the pandemic, according to property company Savills. Shoppers who stroll along the curving avenue in London’s West End, passing through Oxford Circus and Piccadilly, may notice the absence of familiar brands. J Crew, Brooks Brothers, Desigual and Zara Home all closed during the two...