It stands up because the writing is exceptional and the risque tone of it is expertly delivered on stage.
Kenneth Williams, in particular, seemed to go about his role with such relish that it almost sounded as if he'd been freed from some terrible secret.
Many years later, after his death, his private diaries would reveal a man at tremendous odds with his own sexuality.
Imagine that; imagine not being able to live out the true meaning of your life with the same freedom as most other people. Imagine having to keep your true identity a secret.
I wouldn't wish that on anybody.