Regardless of what file names, etc, say, the end result is that the files are not compressed to any degree that makes any practical difference.
For example, my current file size (on disk)
.ftm = 227,592
media folder = 13,234,806,784
Total to = 13,235,034,376
the ftmb file from these = 13,309,116,416
This shows the ftmb file is GREATER than the grand sum of the two original file/folder combination.
There is nothing wrong with using the backup and restore routine. It is simply unnecessary. Copying the actual files themselves will do the job just fine.
If you are using an external drive to regularly backup all of your Documents folder to, then copying all of your Documents from the external drive to the new computer will result in all of your files being transferred to the new computer and ready for duty - including word, excel, and all of your other files.