The user could be told what's going on without breaking the entire flow through. That's what status bars did. Even if they're not the answer now, there's endles

The user could be told what's going on without breaking the entire flow through. That's what status bars did. Even if they're not the answer now, there's endless ways to notify a user of action. The old rotating "e" of Internet Explorer. A progress bar embedded next to the relevant part that's loading. A tick mark that shows up then fades away when an item is done. Etc etc