Thats right. But still the tarballs are easy to find.
Let's say I am looking for orca:
https://sources.debian.org/search/orca/
The name for Debian is gnome-orca. Let's go there:
https://sources.debian.org/src/gnome-orca/
I am interested in the most recent release:
https://sources.debian.org/src/gnome-orca/3.26.0-2/
Now I click on PTS (Package Tracking System) in the small package info frame on the right:
https://tracker.debian.org/pkg/gnome-orca
Then I click on the link to the source in the General tab:
https://packages.debian.org/search?s...rds=gnome-orca
Then at the bottom I can either click on sid and find the links to the source tarballs, or on gnome-orca to find the link to the binary package.
That can seem a long way, but it takes less time to actually do it than to write that down
Actually I have already packaged orca and I took the source tarball directly from a Gnome repo but that's just an example...