We live in a rapidly changing culture where “plays” are often seen as slightly passé when set against an inclusive, all-embracing concept of “theatre”. The lonely eminence of the writer is also increasingly challenged by a number of external factors: directorial power, the celebrity culture, the growth of group-devised and site-specific work, advances in new technology. With the exception of our insane deification of minor celebrities, none of these things is inherently bad. To date, dramatists have survived rather well our continuing redefinition of theatre. The big question is whether they will continue to do so.

Dramatists, like actors, sometimes speak darkly of the “directocracy”: the supposed band of power maniacs who virtually control the means of production in British theatre. But, looking back, I would say that living writers have gained more than they have lost from partnerships with particular directors. They may not have been made in heaven, but the creative marriages between, say, Pinter and Hall, Shaffer and Dexter, Storey and Anderson, Nichols and Blakemore, Hare and Eyre worked to the benefit of both parties.

With the exception of Alan Bennett and Nicolas Hytner, Tom Stoppard and Trevor Nunn, there seem to be rather fewer such alliances in our promiscuous, contemporary culture. Not only that, there are hints of a return to the principles of Antonin Artaud who envisaged a future in which the typical language of theatre would be “constituted around the mise en scène” and where the director would became an all-powerful auteur… In the end, I would gamble on the dramatist outlasting the auteur-like director, simply on the grounds that plays have an emotional resonance you rarely find in engineered spectacles and that in Britain there are few directors equipped to assume the role of Artaud’s “unique Creator”.

Far more insidious is the cult of celebrity which corrupts virtually every aspect of British life and which certainly affects the theatre. It has become increasingly difficult for a straight play to succeed in the West End without a big name attached; and, where once that would have meant a star of the calibre of Maggie Smith or Judi Dench, it now refers to someone known simply through film, television or the all-pervasive gossip columns.

It could be argued that the dramatist benefits from celebrity-casting and that the results are not always harmful. When Daniel Radcliffe played the horse-blinding boy in Peter Shaffer’s Equus, he showed a surly authority even though there was something creepy about the slavering press attention to his brief moment of on-stage nudity: the world seemed astonished that the cinema’s Harry Potter actually had a penis.

When Billie Piper, best known for her two seasons in Doctor Who and her marriage to Chris Evans, appeared as Ann in Christopher Hampton’s Treats, the play was upstaged by the traumas surrounding the star’s private life. Admittedly, Piper’s failure to appear at two preview performances fuelled various rumours. But it was distressing to see the Observer, instead of asking its drama critic to review the play, despatch a showbiz columnist to cover the event and chart, in breathless detail, all the stories about Piper’s mystery illness, suspected pregnancy and off-stage relationship with one of her co-stars. Tittle-tattle replaced analysis and Piper, like Radcliffe making her stage debut, was given an attention that Sarah Bernhardt in her heyday might have envied.

Piper may well turn out to be a fine stage actress. What troubles me is the tenuous connection between fame and achievement: something that prompted Dame Edna Everage to remark, in her latest guest-crushing TV show, that “celebrity is the new nonentity”.

Michael Billington is drama critic of the Guardian and has been voted the UK’s top critic by Whatsonstage.com theatregoers. He’s also a columnist for our sister print title What’s On Stage Magazine (click here to read his columns to date). State of the Nation is published by Faber & Faber (priced £20). Billington discusses issues raised in the book with NT artistic director Nicholas Hytner in a Platform event at the National Theatre on 19 November 2007.