There are some concepts clashing here.
I mean, if you let the LLM build a testris bot, it would be 1000x better than what the LLMs are doing. So yes, it is fun to win against an AI, but to be fair against such processing power, you should not be able to win. It is only possible because LLMs are not built for such tasks.
Task: play tetris
Task: write and optimize a tetris bot
Task: write and safely online optimize a tetris bot with consideration for cost to converge
openai/baselines (7 years ago) was leading on RL and then AlphaZero and Self-Attention Transformer networks.
LLMs are trained with RL, but aren't general purpose game theoretic RL agents?
Fun fact: Humans were not build for playing Tetris either!