Does it need to be attached, or would a Bluetooth headset meet your needs?

I think it depends on the humans. Personally, I find online interactions more comfortable than in-person ones, most of the time. In-person interactions exhaust me, if they aren't with the small handful of people with whom I'm most comfortable, so I can really only take them in short doses. I can chat online without any such issues, so if I were lonely, a companion A.I. that could carry on actual conversations might really help, even if it isn't a 1:1 replacement for human interaction.

I'm aware that I am probably not representative of the majority of people, but I doubt I'm the only one who feels the way I do, so there could be a place for this sort of thing, where it could do some actual good.

CTEs can be useful, particularly in PostgreSQL, where there are writable CTEs, but a lot of the time, I prefer using temp tables over CTEs, as they often perform better for larger datasets. I think one of my favorite constructs is window functions. I've found many uses for them, over the years.