I’ll be first to say synchronised swimming, as despite the effort and training which undoudtedly has to be put in, it is no different to say ballroom dancing IMO.
I think tennis, football, basketball too as they have been ‘pro’ too long and have their own more important events for the Olympics to be of any real value. IMO they are not really ‘in the spirit’ of The Games……if that still has any relevance in the highly commercial jamoboree it has been for a very long time!
EDIT – what Zulu said re style points is spot on but removing any assessment by judges would cause a problem with diving and gymnastics!