I’m not sure I understand the question. OctoPi is an OS for RPi based on Raspbian (Raspberry Pi OS) that bundles OctoPrint and a few related applications.
OctoPrint connects to a 3D printer over a serial (over USB) connection. It controls and monitors your 3D printer via a web interface. OctoPrint is extensible with plugins and has a very active community including Discord.
One plugin I use is a firmware updater. Normally this function is performed (for Lulzbot printers) by CuraLE but since my printer is attached to the RPi and not to my desktop where I run Cura, it is more convenient for me to upgrade the firmware through the RPi (the printer and my desktop are located in different rooms).
OctoPrint is worth it to me because many print jobs are multiple hours in duration. While the RPi is happily tending to the printer, I’m free to use my desktop without worrying about if it will interfere with the printer. The first time you have an overnight print interrupted by a Windows update you will understand.