This sound comes from Undertale, the 2015 indie RPG created by Toby Fox. The game's simple retro sound design made many of its effects easy to recognize outside gameplay, and the damage cue spread in meme edits and short videos as a clean way to signal a hit, loss or emotional sting. It is still popular because the clip is extremely short, readable even without context, and familiar to players who also know other iconic game reaction sounds like the Roblox oof.