Why don't smart speakers have USB type C?

For example, Amazon echo and Google nest mini have proprietary barrel charger plugs.

What is the point of a proprietary barrel charger plug on a device like a small smart speaker which may be occasionally moved around? It makes much more sense to have USBC, the common connector,for power on those devices, and yet, stupidly, they have a proprietary charging port. It makes zero sense to me. Does someone care to explain this to me?

Why does Amazon echo not have USBC?

Why are there proprietary barrel charger supporters

The whole point of USBC was to be the one connector for everything

#usbc
#usbcpowerdelivery
#usbtypec
#usb4
#commonport
#oneconnector
#1connector
#onecommonconnector
#onecommoncharger
#standardization
#consumerelectronics
#smartspeaker