From the article that Bill posted:
"In February the organisers of the world music festival Womad said they were struggling to book artists because of Brexit uncertainty and concerns about difficulties entering the country. Chris Smith, the festival’s director, said: “It is harder to book artists because of Brexit … We are struggling to overcome it and let artists know they are welcome here and that people still want to experience their great music.”
Seems pretty plain to me. And whatever side people take on Brexit, it's already had a detrimental impact on the UK's economy. Companies are leaving or deciding not to base themselves there because of it.