Web browsing on Mac slows down after a few days of use
I have the Cisco AnyConnect agent installed, which is only used for VPN and not Web Filtering. Still, the acwebsecagent process is running and slowing down my web browsing.

To uninstall acwebsecagent, run:
sudo /opt/cisco/anyconnect/bin/websecurity_uninstall.sh

Credit to this post for the above command.