Either the engine was misconfigured, the hardware you were playing on was glitching or you are omitting something. There is no chance in the world that you can beat stockfish in standard time control.
I'm sure some of those games are actually stockfish v stockfish or something similar. Its pretty easy to run stockfish or lichess locally and copy the moves from each engine back and forth.
Sure, some people are cheaters. Some are not. There is no personal win in cheating against Stockfish. Usually strong players do it for training purposes, or to entertain their watchers when they stream. I actually remember having seen one who did that, and he drew. That was a party.
Evidence given: "There exist some small number of games on lichess.org played against stockfish where the user won."
My counter argument is that games on lichess against stockfish don't imply a human beat stockfish. It could just be that stockfish (or other bots) can sometimes beat stockfish. And some humans surely use bots to play on their behalf in order to cheat in online games.
I don't know if any humans can beat stockfish. But I don't consider that to be strong evidence.
To assume that a human can beat that is just delusional.
Especially pre-NNUE, chess engines were often not fully well-rounded, and therefore a human with specific knowledge of the chess engine's weaknesses could take it down with enough attempts.
Also, Lichess' Stockfish runs in the browser (with all the slowdown that entails), plus is limited to one second of thinking time even on the highest level. It also has no tablebases and AFAIK no opening book. Even if you _can_ consistently beat Lichess Stockfish level 8, there's still a very long way from there to saying you can beat Stockfish at its maximum strength, which is generally what people would assume the best humans would be up against in such a duel.
People generally don't play unencumbered engines anymore because the result isn't interesting.