Yes, Starship is unproven. But Falcon Heavy is very real. > If SpaceX fails as a company after some accident like [starship failing and killing people], the SL

Yes, Starship is unproven. But Falcon Heavy is very real. > If SpaceX fails as a company after some accident like [starship failing and killing people], the SLS will just continue to plod along. Well.. yes. But note also that if SLS crashes and kills a bunch of astronauts it will certainly plod along too. That's what the Shuttle did. The difference being one of NASA/Boeing and SpaceX are accountable for killing astronauts, while the other is not.