If there was one big problem w/ today's LLMs it is that the attention window is too short to hold a "complete" document. I can put the headline of an HN submission through BERT and expect BERT to capture it but there is (as of yet) no way to cut up a document up into 512 (BERT) or 4096 (ChatGPT) token slices and then mash those embeddings together to make an embedding that can do all the things the model is trained to do on a smaller data set. I'm sure we will see larger models, but it seems a scalable embedding that grows with the input text would be necessary to move to the next level.