If I were to remove someone from a shared folder, do they take their files with them?
No. The files will remain in the folder, but they will also remain to be owned by the user who left. That user will not see the folder in their Google Drive, but they will be able to find the files by using
is:unorganized search (which is meant precisely for finding such orphaned file). From those search results, they will be able to edit or delete the files. And when the file owner deletes a file, it's gone for everyone.
To avoid potential file deletion, you want to make sure every file you need is owned by you (or someone who remains in the company). This can be achieved if either
- The departing worker transfers file ownership to you.
- You make own copy of the file.
The first version is preferable, as it preserves the revision history; making a copy of a file does not.
By the way, transfering ownership of a folder does not imply the same for the files it contains. It's best to think of Google Drive folders as labels: they are convenient for organizing things, but do not really "contain" them.