Lossless information transfer between humans may be possible, but it's certainly not free with respect to work and time, and it's certainly not the default.

For instance: Whenever I want to communicate a thought or an idea, for instance verbally or on paper, I find that I must first apply some work-intensive, lossy compression which outputs bad English. The output invariably looks or sounds much worse in comparison to the uncompressed idea I have in my head. Throughput is abysmal. A few minutes of thinking can sometimes require a few hours of writing in order to be communicated with some lucidity. In order to restore some similarity to the uncompressed idea as it appears to me, I need to apply further work-intensive error correction, and repeatedly compare the revised output to my internal model.