I would expect at the larger major shows a bike should be as near to factory shipping as possible, clean and polished.
For all other events put your bike in for judging being aware of the kind of show it is, for example
Brunton - near me, a steam and vintage rally, bikes judged by John Reynolds uncle I believe, can't argue with his choice ( my two mates got best in show and best in class) - the judge likes authentic and realistic for age
Peebles - the public fill in a voting slip in the back of the program, one vote for each class, the public are 99% bikers so it's not a case of the prettiest bike, although marque loyalty comes into play.
Glendale - nearer to me, another vintage tractor rally with four classes, tractors, bikes, cars, commercial, with the cup going to each class in turn yearly and last years winner picks this years winner.
of those I prefer Peebles, just more fun
My bike is often very shiny, but also often very grotty ( farming country, lots of cattle, mud and other stuff to protect the tarmacadam

) but it gets ridden, gets fettled and gets polished, all very therapeutic ( well apart from that bottom maggie nut)
End of the day though, it,s your choice