Why is SCSI opcode 0xA1 (ATA_PASS_THROUGH) sent?

I'm writing my own USB BOT device driver, and I'm receiving the SCSI opcode 0xA1, which isn't defined in SPC or SBC, but rather in the ATA Command Pass-Through specification. Even WireShark doesn't recognize it.

What exactly is the significance of this command? From what I'm getting, it's to bypass protocols or something, but I'm not exactly fluent in IT terminologies or 90s history here. I'm on Linux Mint 21.3, if that's of any relevance.