I expected the -48VDC telco standard to become popular as people had more solar, batteries, etc. I guess we will get there the most complicated way possible with usb-c.
(I suppose a lot of people in the US still probably do have landlines, but I know very few, if any, people who do.)
Then again, my house (built in 2009) is still wired for a landline, but the wires (and the voltage on them) remain unused...