I will defend the OP here, and say that LA-SF trains indeed make little sense, when perfectly good sunk-cost airports already exist that allow various airlines to compete over that route on price and features. Trains are more susceptible to disruptions along the route, because the route itself is more anchored to a particular geography, not to mention they cost a lot to build out to the satisfaction of being truly competitive with airlines if the infrastructure and level-of-service is lacking at this time (which it is).

However, where a train does make sense, is connecting other points along the route.

Air travel tends to be either hub-and-spoke between busy hubs and tiny spokes, or point-to-point between two busy points; rail travel, however, is always along a route that allows intermediate points to be served at similar levels-of-service as major destinations.

Whereas a Sacramento-Bakersfield journey would typically require at least one hop to SF or LA by air, train (and roads, for that matter) allow that journey to be taken without intervening hops, and serviced at a marginal cost, because the two lie along a route that a train would travel anyway. That ability to connect ancillary cities is where rail travel really shines, in ways that air travel can't currently mimic.

Are trains safer? I am not sure the statistics support that.