Last modified on Tue 9 Mar 2021 04.00 EST What do David Walliams, Lil Nas X, Ricky Gervais, Dermot O’Leary, Geri Halliwell, Bruce Springsteen, Miranda Hart, Greg James, Chris Hoy, Frank Lampard, Clare Balding, Konnie Huq, Marie Kondo, Paul McCartney, Julian Clary, Whoopi Goldberg, Ben Fogle, Tom Fletcher, Julianne Moore, Lupita Nyong’o, Sandi Toksvig, Natalie Portman, Spike Lee, Fearne Cotton, Russell Brand, Pharrell Williams, David Baddiel, Simon Cowell, Danny Baker, Prince Charles, Coleen Rooney, Madonna, LeBron James, Lorraine Kelly, Ben Miller, Sarah Ferguson, Adrian Edmondson, Jamie Lee Curtis and Keith Richards have in common? They are all children’s authors. And celebrities. Which makes them, depending on who you speak to, either the saviours of publishing or proof of its decline. And of the many celebrities who have tried their luck in children’s books, Walliams is the giant. Since his 2008 debut,