I had also tried that but some repos still get fairly big and all I wanted was the code not the .git since I am not a proper developer. To your point they can still be quite large.

    cd /dev/shm/block && git clone -j4 --depth=1 --branch=master https://github.com/firehol/blocklist-ipsets.git

    du --max-depth 1 -hc
    24M ./ipip_country
    4.0M ./ipdeny_country
    9.6M ./ip2location_country
    6.9M ./geolite2_country
    25M ./.git
    140M .
    140M total

It's not awful but I currently keep up to date copies of about 300 git repos and if I keep all the big ones it can add up to several GB of data I do not need. For now I just clone to a ramdisk and whack the .git directory for several of the big ones before I rsync back to disk. I probably lose some interesting history doing that.