Being able to blacklist and whitelist on the fly without reloading and waiting ~3-10 seconds for the page to load would be pretty useful, especially when a huge amount of traffic is being generated at any given time (as would being able to avoid ssh'ing into my pihole host so frequently)
I should note that I'm not talking about
pihole -t or
tail -f /var/log/pihole.log | grep $ipAddress or pi.hole/admin/taillog.php. This is a use-case outside of those options.