I don't know how much better AI can do in practice.
If you sit down and really think through how an intraframe compression technique works - something like JPEG or MPEG - You may come to the conclusion that we are already playing with the fringes of our reality.
Consider The DCT and quantization. When a piece of information is transformed by The DCT, we talk about "energy compaction". That is to say, we took a block of information and determined how to represent it as a perfect (lossless) arrangement of amplitudes at given frequencies. This results in most of the important information (in human terms) condensing around the DC component in the top-left corner. We then use something explicitly engineered (i.e. 'trained') on the human visual system to quantize these figures into levels the computer can tolerate (incurring loss). Zig-zag encoding is practically an emergent mathematical mandate at this point...
Then, take a long look at how we are doing interframe compression. Forward & backward difference frames, frames that are differences of differences, predicted vectors of information, etc. A lot of this is very obvious, but there are tradeoffs to be made that perhaps a human should be in charge of - I.e. subjective measures of latency in video streaming relative to group-of-picture size.
Consider this - How could an AI system improve on techniques that optimize for the Human Visual System? A very large part of our multimedia compression today comes from strategically sacrificing information that is subjectively worthless to humans.
All that said, I am sure you can find some low-hanging fruit. For example, if you go and ask ChatGPT to make JPEG work better, it may helpfully suggest swapping Huffman for arithmetic coding. Not exactly a groundbreaking discovery in my book, but it would make a big difference.