Why Mi Mover doesn't move apps but samsung smart switch can?

I move all apps to mi mover. 1. Some apps are moved 2. Another apps have a message "not installed" This is weird. The whole point of using mi mover is so I don't have to reinstall all those apps one by one. So I reinstall one by one. Then I tried to move the apps again. Now it seems to be working. However, when I open whatsapp in the new phone I do not see my old whatsapp. I basically have to input my phone number again and uses back up again. So basically it's useless. I have to reinstall every app and move them like normal like usual. So what's the point of using mi mover? When I use samsung switch I think I got things moving quickly. Why the differences?