Does Packaging Cook Everything In My content Directory

I just packaged a project I have been working on for the last month.
It is one simple level. Probably about 50 Static Meshes, 3 Skelmeshes,
Maybe 100 materials, the whole level had 300k tris. A small level.

I was expecting a file size in 500MB range.
It is huge. Total size is 4GB.
And that was with the “Create Compressed Cooked Packages” option selected.
10GB without it.

While I was building the level. I added the whole infiltrator demo assets, and
elemental demo. I ended up using a few meshes from both of them. But most
of the stuff I moved over is unused.

Does having extra unused assets in my content directory increase the cook size?
If yes is there anyway to automatically remove all unused assets from that directory?