> The overall disk usage for trixie is 403,854,660 kB (403 GB)
What does this mean? If all 69k+ packages are installed, it will take up this much space?
The 403GB figure represents the total size of all source packages in the Debian archive, not the disk space required for a typical installation which is usually under 10GB for a desktop system.
As this also lists lines of code, it sounds more like sources plus packages. Think space that a full mirror (src + generic + arch specific packages) would need.