And it can't cache tokens because all tokens are evaluated in the context of all the other tokens, so they don't have the same representations when they reoccur at different positions.
But, yes, tokens are chosen one word as a time based on the previous content, similar to earlier auto-completion algorithms.
Can you say that about any other task in ML? When Inceptionv3 came out I was able to run the model pretty comfortable on a 1060. Even pix2pix and most GANs fit comfortably in commercial compute, and the top of the line massive models can still run inference on a 3090. It’s so unbelievably ironic that one of the major points Transformers aimed to solve when introduced was the compute inefficiency of recurrent networks, and it’s devolved into “how many TPUs can daddy afford” instead.
However the upside to pocket sized intelligence will eventually win out. It's just a question of when someone will scrape together the required investment.
If you mean putting the model weights into gates directly, it’d be useless because users would get bored of the model as soon as they figured out what its style looked like. Also, large models can memorize their training data so eventually you’ll get it to output something copyrighted.