Like most cities, LA's public transit system used to be a privately-owned, for profit network, mostly from Pacific Electric and Los Angeles Railway. By the 50s, those companies had shuttered most of their routes because of competition from private cars and buses, so eventually they were bought by local government and became the public transit system.

Same thing happened in Chicago. Before there was the CTA, there were private, for-profit rail roads connecting the city, owned mostly by the Chicago Rapid Transit Company.

So, if Via is unsustainable and unprofitable, and was acquired by local government, that wouldn't really be any different from how the LA Metro got started.