[AceJohnny2]

There is a field of competitive compression algorithms, where time and computation are not factors. People have made compressors that take hours (days?) to compress the test corpus.

A long-running kinda-joke in the field is that the upper-bound of compression is "AI-complete", where instead of compressing, say, the text data of the complete works of Shakespeare, the compressor just encodes "The Complete Works of Shakespeare", and the AI decompressor re-generates the output from that prompt.

With the advent of LLMs, Bellard just made that joke a reality.