> The only service performing well is a closed source one that could simply use a real chess engine for questions that look like chess, for marketing purposes.
That conspiracy theory holds no traction in reality. This blog post is so far the only reference to using LLMs to play chess. The "closed-source" model (whatever that is) is an older version that does worse than the newer version. If your conspiracy theory had any bearing in reality how come this fictional "real chess engine" was only used in a single release? Unbelievable.
Back in reality, it is well known that newer models that are made available to the public are adapted to business needs by constraining their capabilities and limit liability.