“Architecture is a visual art, and the buildings speak for themselves.” Julia Morgan
The curved bow (bay) window was intended as an ornamental part of a building rather than a functional one.
A feature of Victorian architecture, the style migrated to countries where the English had a presence, like South Africa. They’re to be found mainly on older houses, although there’s been a resurgence in the residential market. Contractors will bash out the current window and build in a bay window all in 1 day.