I'll give my view based on previous career as ex-engineer, and ome things explained in the grey mists of time from college...
The term bus derives from omnibus. A latin expression or term, Omni, essentially 'for all'. ie Omnipotent, Omnidirectional, etc
Later, the bus (transport) being a bit of a simplification, mainly meaning a carriage for everyone. It was I believe originally refered to as the omnibus.
The term 'bus became commonly used in electrical and electronics meaning essentially the same thing. Presumably, a bus to get something from place to anywhere/everywhere on a route.
Databus- same data for everything that needs it.
Busbars. the same power source for everything that needs it.
A bit over simplified, but I think thats it.
SSD