I was socked by the size of the following file
ls -lh /usr/lib/locale/locale-archive
-rw-r--r--. 1 root root 107M Jun 8 11:07 /usr/lib/locale/locale-archive
but I was socked more that even after stripping it the total compressed image size did not change at all (because more of the content of that file is redundant and compressible)
moral of the store: don't look to base image size as metric