Reaction sounds like this became popular as short spoken replies replaced longer clips in fast edits, group chats and livestreams. A single thanks works across many situations because the meaning is clear even with the video muted or cropped, and the short length lets creators stack it with other reactions without slowing the pace. It is now used both sincerely, to acknowledge help or support, and playfully, when the favour is tiny or obvious, giving editors a polite punctuation mark that audiences understand immediately without any context or setup needed.