There is a huge difference in voice recognition accuracy between macOS and iOS. I don't know if this is because I use dictation more frequently on iOS or because they use a different engine on the two systems. To benefit from the good results on iOS I dictate my texts to Notes on iOS and paste it to whatever app on macOS by using the virtual clipboard (aka Handoff). But that is not a very smooth workflow.
Is there any way to use iOS dictation on macOS? Or to transfer some sort of "user database" from iOS to macOS? Must be a common problem.
(I still use macOS Mojave 10.14.6. But I can't imagine that Catalina will make any difference…)