There is a legit phenomenon in chess of "assistants" that are literally just Stockfish telling you which moves to play. People still want to play chess against untrusted opponents. Real-life chess tournaments generally make people surrender their electronics at the door for this very reason.

Fortunately, most cheaters don't know how or are not trying that hard to hide, and are identified by pattern recognition. It's not that big a problem in practice. It's still universally considered cheating.