Howard Oakley notes a dictation issue in Catalina (among other Apple issues):
Eclectic Light Co. said:Dictation, resources, and change
... Where the new Voice Control features fall short is in dictation. You can still – if you don’t turn Voice Control on – opt to enable the old Dictation feature in the Keyboard pane. But Apple has removed the Enhanced Dictation feature which has been so successful and widely used. Your experience of using the new dictation available in Voice Control may be very different to mine, but I was coming close to needing anger management classes in the few hours that I grappled with the new feature.