because it's a separate context window, it makes the model bigger, that space is not accessible to the "user". And the "language understanding" basically had to be done twice because it's a separate input to the transformer so you can't just toss a pile of text in there and say "figure it out".

so we are currently in the era of one giant context window.

Also it's not solving the problem at hand, which is that we need a separate "user" and "data" context.