Redhat made the scripting for you. I don't think it's that complicated of a script (although it would be easier with a retry command)

    sleep $random
    for i in 1 2 3 4; do
      backup && exit 0
      sleep 15m
    done
    logger "backup failed"
    exit 1

add script to @startup in crontab or whatever they use. You can use another wrapper that only execute it if the backup is newer than now-24h. Backup could even be remote and you could track it by touching a file in /var

Yes systemd might be slightly easier, but that's because they put a lot of money into systemd, not because systemd is a better architecture. It's nice that they open sourced it (although it does give them a competitive edge), but we can't act like what used to be there isn't as good.

Someone could have packaged utility wrapper scripts in much less time than it did to add those features to systemd, and these wrapper script would be more widely usable (by init scripts, cronjobs, etc)