"Google, Amazon, et. al. don't care about your personal conversations. They don't want a recording of what you say or do in the privacy of your own home."
Of course they do. The marketing value of doing that would be incredible. Seriously, spend some time reading websites aimed at marketers: a shockingly large percentage of what you read are about how important it is to learn everything possible about people's private lives so that information can be used to manipulate them.
"The bandwidth and storage requirements are too high"
Perhaps, maybe, right now. But is so, the odds are overwhelming that this will become economical in the near future.